The first thing I noticed is that they dance separately and not touching from the beginning until towards the end when it begins to rain and they go into a ballroom position. He also dances around her during the middle like a mating dance from nature. He gives her what she wants gradually, to be seen as a equal in the relationship. Then they come together as partners in the dance and the relationship.
During the Depression, women were emerging into the workplace as well as being at home. Times were changing. I think this theme is in all their movies.