I think that this film definitely takes the audience away from their current circumstances. The most obvious is the indulgences that money is spent on. For example, theater, fancy clothing, bell hop, a huge boquet of orchids, etc. During the depression, spending money on these things would have been unheard of, and people were worried about their financial situations. Therefore, being transported to a world where finances are of no consequence would be a welcome relief to the viewers of the time.
I imagine some of the themes would be money, lavish lifestyles, romance, jealousy, etc.