As the essay is focusing on stagecraft, you need to talk about the stage directions that Rose uses in the play rather than the dialogue. This is a particularly interesting question because it is asking you to focus on the genre of this work rather than the language that is used to convey message and themes. The clear message of this play is the way that justice, supposedly impartial and "blind" to our prejudices as humans, is actually in significant danger of being swayed and influenced by those very prejudices. This is clearly shown through the conflict between No. 3 and No. 8. It is of course No. 8 who acts as the voice of reason and tries to do his job properly as a juror, not wishing to convict the defendant as being guilty until he has exhausted any other possibility.
No. 3, by contrast, wants the defendant to hang, whether or not he actually committed the crime. Note how in the final stage directions before the close of the play, No. 3 responds to No. 8's proving that there is reasonable doubt that the defendant committed the crime:
Slowly he moves toward the door. He stops at the table. He pulls the switch-knife out of the table and walks over to NO. 8 with it. he holds it in the approved knife-fighter fashion and looks long and hard at NO. 8, pointing the knife at his belly.
This is clearly a very tense scene, but one which symbolically reinforces the message of Rose in this play. Justice is a very fragile concept and can easily be overthrown by the thoughts and actions of jurors such as No. 3 who allow their judgement to be ruled by their prejudices.