The answer is:
help the reader understand Farquhar’s experience and emotions
In the excerpt from "An Occurrence at Owl Creek Bridge," the author Ambrose Bierce provides a detailed and slow paced account of Peyton Farquhar’s physical pain as he is suspended from the bridge and falls into the river. As a result, readers can sympathize with Farquhar and get to know his perceptions and despair at the moment of his execution.