Rebecca and Mrs. de Winter
Maxim's two wives, the two Mrs. de Winters, are constantly being compared to each other. Our narrator even ends up (accidentally) becoming Rebecca's double at the costume party. At first, it seems to our narrator that she's always being seen as less than Rebecca – less beautiful, less skilled, and less loveable. But later we see that that our narrator's innocence and lack of sophistication is a positive thing, compared to Rebecca's dark and manipulative ways.