In the play, Stanley's eavesdropping adds to the tension by revealing that he is paying close attention to the actions and conversations of the other characters. This can create a sense of unease and mistrust among the other characters, as they may feel that Stanley is trying to gather information about them for some ulterior motive.
Eavesdropping can also contribute to the play's later events by providing Stanley with information that he can use to his advantage. For example, if Stanley overhears a conversation that reveals a weakness or vulnerability of one of the other characters, he may use this information to manipulate or exploit them. This could lead to further tension and conflict within the play.
Overall, Stanley's eavesdropping serves to increase the level of tension and uncertainty within the play, as it suggests that he is not to be trusted and may be scheming behind the scenes. This can add an element of intrigue and drama to the story and contribute to the development of the plot.