In Letter 31, Celie describes Harpo's behavior as he watches Sofia leave. Walker utilizes imagery in this scene to communicate the nature of Harpo's self-inflicted misery:
Harpo sit on the steps acting like he don’t care. He making a net for seining fish. He look out toward the creek every once in a while and whistle a little tune. But it nothing compared to the way he usually whistle. His little whistle sound like it lost way down in a jar, and the jar in the bottom of the creek.
Walker illustrates the change in Harpo's mood through imagery: his whistle sits at the bottom of the creek, encased within a jar to muffle the sound. Figuratively, this communicates that Harpo has lost his typical exuberance. His mood is grim indeed, made all the worse by the fact that he only has himself to blame. Harpo's attempts to impose patriarchal gender roles onto his relationship with Sofia result only in misery.
Walker uses Harpo's relationship with Sofia—in particular, the circumstances that lead to their parting—to illustrate the toxic, generational effects of patriarchal masculinity. Despite being the man in the relationship, Harpo's attempts to dominate Sofia weaken rather than empower him, leaving him alone and depressed.
In Letter 55, Nettie describes an encounter she had with Sofia in town. Nettie uses imagery and figurative language to relate her impression of Sofia's odd behavior to Celie:
[T[here was [Sofia] looking like the very last person in the world you’d expect to see waiting on anybody, and in particular not on anybody that looked like [the mayor's wife]. I spoke. But just speaking to me seemed to make her embarrassed and she suddenly sort of erased herself. It was the strangest thing, Celie! One minute I was saying howdy to a living woman. The next minute nothing living was there. Only its shape.
In the above passage, Nettie uses visual imagery to describe Sofia. These descriptions conjure up an image of Sofia as barely there—a wraith or spirit of some kind, no longer in the physical world. Sofia has been so degraded, dehumanized, and belittled by her imprisonment and subsequent enslavement (in all but name) that she has retreated inside herself, away from the abject miseries of everyday life. The imagery in this passage clearly illustrates Sofia's disassociation from reality, a strategy many enslaved people were forced into as a means of preserving their dignity and rich inner life.
Letter 55, penned by Nettie after her ship docks in Africa, includes an interesting reflection on the parallels between letter-writing and prayer. The following passage from Nettie's letter utilizes figurative language and sensory imagery to equate the two processes:
And whether God will read letters or no, I know you will go on writing them; which is guidance enough for me. Anyway, when I don’t write to you I feel as bad as I do when I don’t pray, locked up in myself and choking on my own heart. I am so lonely, Celie.
While Celie writes her letters to God, Nettie writes her letters to Celie. She views her sister as a kind of higher power, a form of accountability and someone who will serve as witness to the acts of her life. Both prayer and the act of writing letters to Celie are important forms of confession to Nettie. She uses these confessional media to process new experiences and complex emotions. If these internal feelings remain "locked up" inside of Nettie—neither communicated nor confessed—she feels that she might "[choke] on [her] own heart." This vivid sensory imagery emphasizes the importance of having one's life witnessed, whether through interpersonal relationships or spirituality. When a person lacks the ability to express their emotions externally, they suffer.