The structure of the play involves the presentation of the scenes through the memory of one of the characters. Tom Wingfield is both the narrator and a character in the play. The separate scenes, then, should be seen as part of Tom's memory of a crucial time in his life. The scenes do not function to give us a traditional plot or story-line, but, instead, they are selected to give the audience a slice of life that the author once lived through. In his own world, he wants to present truth through illusion; that is, he wants to try to say something about his life by recalling certain scenes of his past life. Thus the play is structured upon the principle of presenting a series of episodes which should accumulate to make a total comment about a specific life.
This type of structure forces Tom to be both a narrator and a character in the play. He must let the audience know that these are scenes from memory and that he is both the person remembering them and the person centrally involved in the scenes. Some critics have objected to this structure because, as they point out, Tom could not possibly know what happened in the scene between Laura and the gentleman caller. But as Tom suggests, he takes the license of a poet and projects himself into scenes in order to present poetic truths.
The stage directions call for the use of several technical devices in order to convey the idea that this is a memory play. For example, some of the scenes should be presented with some type of net or gauze between the audience and the actors. Or in many places, Williams suggests the use of titles and images to be projected on a scene in order to force or reinforce the idea of memory and to recall certain events that occurred during the time of the play. Others are supposed to be used to suggest some symbolic aspect of the play. But when the play is produced, they are virtually never used. Most directors feel that the play is sufficient without the extra use of images. In fact, most directors feel that the use of these images would detract from the central action of the play. But the point is that Williams included them so as to help with the structure of the play as a memory play.