Through cinema, the viewing audience has been able to see and take note of how sets, particularly those in homes, such as Father of the Bride (1951 and 1991) and Mrs. Doubtfire, were beautifully decorated. The settings inspire individuals to want to decorate their own homes in a similar style. It would be the same, I suppose, for women and men's clothing. People see others wearing a particular jacket, for example, and they go out and buy the same one or close to it.
As for the years that you state, I'm guessing that movies prior to 1940 were largely shown to a viewing audience that really couldn't afford to dublicate the set designs due to The Great Depression of the 1930's.