Notice here the stage direction. As soon as Laura opens the door, she rushes across the room to the phonograph. Her crossing the stage with her limp emphasizes her agitated state. Likewise, her retreat to the phonograph suggests her reliance upon her own world rather than meeting with the new world represented by the gentleman caller.
Jim O'Connor's conversation about his course in public speaking again reveals him to be a rather prosaic character. By this point, it is rapidly becoming apparent that he is no great hero, except to Laura who remembers his great achievements during their high school days.
This scene is the first definite evidence (outside of the prologue) that Tom is actually taking a step toward escaping from his present situation. He has used the money for the light bill in order to pay his dues with the Merchant Seaman's Union.
Notice how Amanda, upon first meeting Jim O'Connor, almost overwhelms him with conversation. Here she displays all the "charm" that she can recapture.
Again, ignoring Laura's feelings, Amanda forces Laura to come to the table. It is not until Laura stumbles and almost faints that Amanda finally realizes that Laura is actually sick.
