Generally, plays do not have narrators. How does the fact that Tom is the narrator affect the style and content of "The Glass Menagerie"?
Tom is not only the narrator, but the protagonist of the play. The play is told from his memory. As Tom points out at the beginning of the play, Tom gives us truth "in the form of illusion." Thus, when seen on stage, parts of the play seem rather "dreamy" and, of course, we see all the action from Tom's perspective. We can only guess what the events would look like from Amanda's, Laura's or Jim's viewpoint. If Tom had not been narrating the events, the audience would have never really know the context of the action or the consequences on Tome of leaving his sister.