Williams opens with extensive stage directions that set the scene of the play. He describes the Wingfield apartment, a small unit in a crowded urban area of St. Louis. Visible outside are a fire escape and narrow alleys flanking the building; through the transparent fourth wall, the audience can see the Wingfield living room and dining room. A large photograph of the family's absent father is on the wall. Also visible is a large collection of transparent glass animals, Laura's "glass menagerie," for which the play is named. There is a phonograph, along with some old records, and a stenography chart with a typewriter. During the opening, the transparent fourth wall ascends out of sight.
Tom emerges, dressed as a merchant sailor. In his first speech, he contrasts himself to a magician, giving "truth in the pleasant disguise of illusion," and establishes himself as a poet and the narrator of the play. He tells the audience that the play takes place in the thirties, when there was war in Spain and a different kind of turmoil in America. He warns that the play is a work of memory, and therefore is not realistic. There will be music, unrealistic lighting, certain events amplified and emphasized. He describes the characters: Amanda, his mother; Laura, his sister; a gentleman caller who will appear later in the play; and Tom's and Laura's absent father, who never appears, but is nonetheless an important figure in the play. Their father occasionally sends the family postcards from all over the world; the last one contained a two-word message of "Hello! Goodbye!" He abandoned the family many years ago.
As the action begins with Amanda calling Tom to the dinner table, the tension in the family immediately becomes apparent. Amanda is a sympathetic character, but she is also demanding of her children and often quite silly - instructing Tom, although he is a grown man whose wages support their family, how to chew his food. Laura tries to clear the table, but Amanda tells her to sit and be the lady while she does the work. As Tom goes out to smoke a cigarette, Amanda tells a story she has often told before, about one day in her youth when she received seventeen gentleman callers in a single afternoon. She names them, tells what they went on to do with their lives, and reminds her children miserably that she, who had her pick, chose their father. She then asks Laura when Laura's own gentleman callers are going to start arriving, and Laura responds nervously that she has none. The question clearly makes Tom uncomfortable. Amanda responds with incredulity to Laura's insistence that she is not as popular as her mother was back in the small town of Blue Mountain. The scene closes with Laura remarking wistfully to Tom that their mother is afraid that Laura will be an old maid.
From the beginning, the figure of the narrator shows that Williams' play will not follow the conventions of realistic theatre. The narrator breaks the conceptual "fourth wall" of naturalistic drama by addressing the audience directly. Tom also tells us that he is going to give the audience truth disguised as illusion, making the audience conscious of the chimerical quality of theatre. By playing with the theme of memory and its distortions, Williams is free to use music, monologues, and projected images to haunting effect. Tom, as narrator, tells the audience that the gentleman caller is a real person - more real, in many ways, than any other character - but he also tells the audience that the gentleman is a symbol for the "expected something that we live for," the thing for which we are always waiting and hoping. This naming of a character as both real entity and symbol is characteristic of Williams' work; both of these aspects of the gentleman caller are important to the overall impact of the play.
The allusion to Guernica and the turmoil in Spain, juxtaposed to the uneasy peace in America, establishes a tense atmosphere as the play's background. The Americans of the thirties lived in relative peace, if economic hardship, but for the 1944-5 audience of the play's first production, the thirties would have been seen as the calm before the storm of World War II. The allusion to Guernica (bombed by Germany, ally of the fascist forces in Spain; the carnage was famously depicted in a painting by Pablo Picasso) serves as a reminder that before long war will be coming to everyone, the United States included.
There is symmetry between the uneasy peace of the time period and the uneasy peace in the Wingfield house. Just as America stirs restlessly with the uneasy peace before the Second World War, Tom seethes with the need to escape his home and set out into the world, as his father did before him. The fire escape, a visually prominent part of the set, is an important symbol for the imprisonment that Tom feels and the possibility of a way out. In his stage directions, Williams characteristically imbues the fire escape with symbolic weight, saying that the buildings are burning with the "implacable fires of human desperation." Tom addresses the audience from the fire escape, and his positioning there, standing alone between the outside world and the space of the apartment, points to the painful choice he makes later in the play. In order to escape, he must escape alone and leave his mother and sister behind.
Originally, the script called for the use of a projector, which, during each scene, showed images to emphasize certain motifs and symbols. This projector was not used in the original Broadway production, but some productions since have used the idea and the instructions for the device remain in the script. For example, while Amanda is speaking, the script says that a projected image of Amanda as a young girl appears. These photographic images and projected text emphasize the symbolic elements of the play as well as the theme of memory; in the case of Amanda's image, we are given memory within memory, a memory framed by the larger memory of the play itself. The audience is therefore twice removed from the world of the image, contributing to the dream-like and ghostly atmosphere of the play. While the projected image gives added force to Amanda's words, showing the audience a visual representation alongside the images created by Amanda's speech, these visual images become symbolic of memory's paradoxical nature. On one hand, the visual image is real, right before our eyes, and full of evocative power; on the other hand, it is only a photograph from a distant past and is therefore frozen and lifeless.
Amanda is always returning mentally to this past, which is immaterial and far-removed from her current reality. Her reaction to Laura shows that she is strangely in denial about the nature of her own daughter. Laura is crippled, able to walk only slowly and with great effort, and emotionally she is terribly fragile. The contrast between the vivacious and talkative Amanda and her timid, soft-spoken daughter could not be starker. Tom has a tender relationship with Laura; when Tom expresses frustration at the start of Amanda's story about her gentlemen callers, it is Laura who persuades Tom to humor their mother.
The relationship between Tom and Amanda is tense. In this scene, he seems to be struggling to tolerate her, and while Amanda is loving, she is also demanding beyond reason. Her insistence that Laura stay put while Amanda plays "the darky" reveals her extremely provincial Southern upbringing. In her youth she was wealthy enough to have servants, but now, with her husband gone, she is struggling to make ends meet. Indeed, she wants to relive her past through Laura, transplanting the quaint life she had in Blue Mountain to the urban setting of St. Louis. Clearly, Amanda seems oblivious to Tom's unhappiness and Laura's painful shyness.