what techniques does emily bronte uses in chapter 20

Structurally the novel is rich and complex throughout. There are two generations of characters, and the themes and relationships of the first generation are reflected in the second but with differences that increase our understanding. Brontë ’s use of point of view leads to many questions about the narrators who control the unraveling of events. It is as if the main characters are seen through a series of mirrors, each causing a certain amount of distortion. Without an omniscient voice controlling sympathies, the reader must get inside the characters’ minds, the one telling the story as well as the one about whom the story is being told. Probing this complex web of relationships and motives leads to intense psychological analysis, and in this way the novel mirrors life itself. Learning occurs in pieces and is always subject to revision. (1)

A complete chapter analysis can be found right here on gradesaver. I've provided you with the link below.