Aunt Emma's wedding dress.
When Aunt Emma is getting Stanwyck dressed in costume for the New Year's Eve dance, we soon discover she is opening a wedding dress that was packed away years ago. Inside one of the boxes is a bundle of letters tied in a ribbon. When Aunt Emma carefully picks up the letters, she gets a far away expression on her face letting the audience know that she had once planned to be married. She cheerfully dismisses Stanwyck's question about the dress by replying, "Oh, I fiddled with the idea one summer but it was over by fall." I really felt sorry for the old maid.
Such a simple scene but it really packs a whallop for me as do so many other scenes, making this movie a real treat.