Lu**** has a way of letting the audience know the mood and conveying what is going on without the camera being on the actors. Even while the camera is on props you understand what he he trying to capture.
In the scene sound is used to set the dramatic tone of the infidelity going. The raised voices, gun shot and loud know on the door all set the tone.
Despite the dramatic beginning of the scene and situation it ends light hearted. Escapism is certain a theme of the depression era musicals as folks were trying to escape their own problems by wither looking at others battle theirs or dreaming of an extravagant life.