In Book 2, Chapter 8, Hardy uses a flashback rife with foreshadowing to describe a new perspective on Thomasin and Wildeve’s wedding. This provides crucial new details about relationships among the characters at this early stage. It also invokes the novel’s theme of miscommunication. The narrator describes that:
The report that Diggory had brought of the wedding, correct as far as it went, was deficient in one significant particular, which had escaped him through his being at some distance back in the church. When Thomasin was tremblingly engaged in signing her name Wildeve had flung towards Eustacia a glance that said plainly, ‘I have punished you now.’ She had replied in a low tone – and he little thought how truly – ‘You mistake; it gives me sincerest pleasure to see her your wife to-day.’
Characters in The Return of the Native are often unable or unwilling to fully understand or communicate their feelings to each other. The flashback to the wedding illustrates this, but it also foreshadows the illicit relationship between Eustacia and Wildeve. The exchange of glances and words “flung” between them are loaded with unspoken tensions and regrets. The narrator notices this, but Diggory, the observer, fails to capture it in his report. Diggory's version of events is woefully incomplete, but not out of malice. It’s because he is unaware of the angry undercurrents between Eustacia and Wildeve. This instance of partial understanding points to a trope of the Naturalist genre that’s central to the book: the notion that people's understanding of events is usually flawed or incomplete, and that this often leads to tragedy.
Wildeve's glance, which says “plainly… 'I have punished you now,” to Eustacia is another moment of foreshadowing. It's the first explicit indicator of the vindictiveness and pettiness that characterizes his relationship with her. The fact that Eustacia responds with "sincerest pleasure" at seeing him married to another woman further points to the future conflict between these two people.