The two answers here are pretty good, but some readers posit that the narrator is in fact the town itself, and not one individual towns person. This is intriguing in terms of your question because it points out the personality of a town and the force it can bear down upon individuals who act within the ideology of the town's structure and self-identification. Reality is created as a town grows, ages, or in this case clings to a past that is hyperbolically represented by Emily and her family. The town has an uneasy relationship with Emily as she represents its past and should on the one hand be venerated, but also physically embodies the psychosis inherent in recovering from a lost war replete with lost ideals and damaged social systems.
“A Rose for Emily” is told from the first person point of view. The narrator is an average citizen from the town of Jefferson, and he is relaying the events of Miss Emily's life. The reader learns information as the narrator gives it. This allows the reader to see the events as the citizens of Jefferson saw them. The townspeople viewed Miss Emily as an eccentric old woman. Not until after her death when the men open the locked room and find the corpse of Homer Barron, do the citizens and the reader realize Emily has gone insane. Therefore the theme of appearance is created because the reader doesn't have insight into what is happening to Emily. The reader makes assumptions just as the townspeople have. The first person point of view creates a false impression of Miss Emily.
The narrator in this story is a first-person participant. The narrator is one of the townspeople, most likely a male, who is very objective in presenting the facts of the story. The narrator tells us about what the townspeople think of Miss Emily at various points in the story, but he does not judge her. He even lends an air of sympathy for Emily, really. One can tell that the narrator does not want to judge her. He is trying to present her situation as objectively as possible. The narrator clearly presents a reality, not an illusion. Miss Emily is the one who is struggling with the concept of reality vs. illusion, etc. She also is living one way while hiding a terrible secret (reality vs. appearance).