What themes and ideas are introduced by the opening stage directions?

It is clear that the stage directions as the play opens present us with the way in which society oppresses humans and acts as a conformist power, making it very hard to hold onto dreams and to break free from its grasp. Note the way that Williams introduces the overall scene:

The Wingfield apparment is in the rear of the building, one of those vast hive-like conglomerations of cellular living-units that flower at warty growths in overcrowded urban centres of lower middle-class population and are symptomatic of the impulse of this largest and fundamentally enslaved section of American society to avoid fluidity and differentiation and to exist and function as one inerfused mass of automatism.

The setting is shown to deliberately inhibit individuality, preventing "fluidity and differentation," and to promote conformism in the "enslaved" people that live in this section of American society. In addition, let us add to this description the author's comment on the fire escape, whose name has a "touch of accidental poetic truth" in the way that all of the buildings like the one that the Wingfield's live in burn "with the slow and implacable fires of human desperation." It is clear, therefore, that issues such as individuality, dreams and the struggles that humans face to try and achieve them and the barriers that try and prevent them from bucking the trend and escaping the enforced conformity of this world are going to be big themes as the play opens and we are presented with a desperate world with desperate characters inhabiting it.