After Mrs. Hale dies, Mr. Hale strokes his late wife’s face and makes soft noises like “some mother-animal caressing her young.” The simile underscores the characterization of Mr. Hale as relatively weak and passive and as more feminine than masculine.
A few days earlier, when Mr. Hale finally realized his wife was fatally ill, the family doctor exhorted him to "be a man, sir," upon which Mr. Hale broke into "manly sobs." Elsewhere, however, the novel doesn't go to such lengths to characterize Mr. Hale as conventionally masculine; in fact, this moment is more of an exception that proves the rule. Once Mrs. Hale dies, Mr. Hale is characterized as markedly feminine.
Likening Mr. Hale to a bereaved "mother-animal" fretting over its young makes him sound especially pitiful and even irrational, as though he can't understand what's happened and can only utter inarticulate noises in response. This is not the language most Victorian authors typically use for a head of family and clergyman, who would be expected to meet such a tragedy with restrained grief and self-possession, offering words of comfort to those around him. That Mr. Hale can't do this suggests that he was right to give up the priesthood, and that from now on, he won't have the necessary emotional strength to manage the household, either. Mr. Hale's irrational helplessness at his wife's death indicates that it will be necessary for Margaret to step up and take charge of dispensing comfort, making decisions about the funeral, and other leadership roles in the future.
After Margaret pays Bessy a visit, Bessy compares her to fresh air and an angel:
I wonder if there are many folk like her down South. She's like a breath of country air, somehow. She freshens me up above a bit. Who'd ha' thought that face—as bright and as strong as the angel I dream of—could have known the sorrow she speaks on?
First Bessy compares Margaret to fresh "country air" in the South of England, implicitly contrasting her with the smoky air of industrial Milton. Not having met Southerners before, Bessy is in awe of Margaret's country origins and feels she can breathe easier, at least metaphorically, in such an outsider's presence.
But it's not just the fact that Margaret has southern speech and manners that's refreshing—it's that she has an air of goodness, like the angel Bessy dreams about and identifies with Margaret. Bessy is surprised that Margaret, with her angelically "bright, strong" face, has experienced so much suffering. She assumes that hardship is easily detected in a person's face, suggesting that it's hard for her to believe that a relatively well-off person from a more pleasant part of the country could know sorrow. While it's true that Margaret has never known sickness or deprivation to the degree that Bessy's family has, she has lost home and loved ones. Bessy's fanciful similes show how much Margaret's friendship means to her, but they also illustrate that assumptions about the North and the South go both ways.
The novel uses a motif of people being described as groups of animals; both sides, employers and employees, do this, showing how class antagonism gets expressed in dehumanizing ways by all parties in Milton.
Mrs. Thornton describes the striking millworkers as “a pack of ungrateful hounds” who want to defeat and enslave their masters, resulting in a perennial “struggle between masters and men.” She also describes the “continual murmur of the workpeople” as “the humming of a hive of bees.” These metaphors suggest, in turn, that her son's employees are vicious animals who can't be trusted, or at best that they're mindless workers, an interchangeable mass instead of a collective of individual human beings.
Later, when John Boucher confronts union leader Higgins, he also uses a dehumanizing simile to describe the union:
[Starve] to death… ere yo’ dare go again th’ Union.’… Yo’ may be kind hearts, each separate; but once banded together, yo’ve no more pity for a man than a wild hunger-maddened wolf.
Boucher acknowledges that union leaders might be good people, but when they start working together as a collective in pursuit of abstract goals, they seem to lose their ability to see individuals and show them compassion—they'd sooner devour a man than help him. While Mrs. Thornton's animal metaphors are based in class antagonism, Boucher's touches on the capacity of crowds to adopt a dehumanizing mob mentality.
Mr. Hale reminisces about the Hales' garden in Helstone, prompting Margaret to recall the spot in greater detail and to feel grief for their old home. The passage uses minute imagery, including the simile of a map, to convey the intensity with which she loves and misses home:
"Do you remember the matted-up currant bushes, Margaret, at the corner of the west-wall in the garden at home?"
Did she not? Did she not remember every weather-stain on the old stone wall; the grey and yellow lichens that marked it like a map; the little crane's-bill that grew in the crevices? [...] and, somehow, these careless words of her father's, touching on the remembrance of the sunny times of old, made her start up[.]
The visual details brought to Margaret's mind are incredibly small, things that the average passerby would easily overlook: weather-stains, the map-like markings created by lichen, and crane's-bill (a tiny wildflower in the geranium family—basically a weed that pops up anywhere and everywhere). The fact that Margaret remembers all these seemingly insignificant details, and that they're enough to bring her to tears, shows how much she cherishes and misses the Hales' old place in Helstone. The lichen marking the old stone wall "like a map" also gives a sense of meaning and purpose to a random pattern. It's not literally a map, but Margaret remembers the pattern so well that it signifies home in her mind.
Notably, these details seem to mean even more to Margaret than to her father. Mr. Hale is more glib about Helstone, his "do you remember[...]" almost a passing comment. Margaret's answering emotion shows how much she identifies herself with Helstone, or at least her memories of what Helstone was like. This connects to the novel's nostalgia theme and further identifies England's South, and Margaret herself, with the beauty and purity of nature.
Nicholas Higgins is telling Mr. Hale about an occasion when his former employer offered him a book of economic theory as a way of shutting down Higgins's complaints about his job. Higgins uses a simile to compare truth to a factory-produced sheet of iron:
“I’m not one who [thinks] truth can be shaped out in words, all neat and clean, as th’ men at th’ foundry cut out sheet-iron [… ]. Folk who sets up to doctor th’ world wi’ their truth, [must] suit different for different minds.”
The manufacturing imagery fits the industrial setting of Milton-Northern and the context of Higgins's daily life as a factory worker. A sheet of iron would indeed be "neat and clean," produced to exact specifications, and each sheet would look just like the next, each destined for similar industrial uses.
However, Higgins perceives that knowledge isn't like an interchangeable industrial product. Different people learn in different ways, so truth shouldn't be dispensed in a uniform way—not if those who teach really want to make a difference. Thus, Higgins's simile connects to the novel's theme of education. Per Higgins, the word of one's "superiors" shouldn't be blindly received, and, moreover, those in positions of authority should respect their subordinates enough to listen to them and respond to their concerns thoughtfully, not in a perfunctory way. Higgins's counsel extends to those who seek to "doctor [the] world": people who set out to improve social conditions shouldn't just hand out obscure theoretical books, but look for ways to connect meaningfully with the people their policies will affect.
On the evening of her visit to Helstone, Margaret reflects on what she's seen that day, and the novel uses a simile comparing death to ripened fruit dropping to the ground.
There was change everywhere; slight, yet pervading all. Households were changed by absence, or death, or marriage, or the natural mutations brought by days and months and years, which carry us on imperceptibly from childhood to youth, and thence through manhood to age, whence we drop like fruit, fully ripe, into the quiet mother earth.
The simile reflects the fact that even in a place relatively untouched by industrial change, like Helstone, some forms of change are inevitable—indeed natural. "Fully ripe" fruit dropping into the earth quietly alludes to Margaret's parents' deaths and suggests that the journey toward death is an organic process, as a person progresses from childhood to adulthood to ripened old age.
The simile is perhaps also a subtle comment on those deaths back in Milton, like young Bessy's and Boucher's, that weren't natural, because those who died were "unripe fruit"—they died long before the natural time, thanks to illness and other inhumane conditions caused by industrialization.
Finally, Margaret's reflections here belie her earlier perception that Helstone hasn't changed. In fact, it has, and change is pervasive, touching every household in one way or another, even if it's not obvious on the surface.