Found this fantastic video essay from Mrs. Pomerantz herself-- apparently, her inspiration for Rich Boy came from her job shining the shoes of rich businessmen in the business district.
There's a lot to be said here, and I'll really let the video speak for itself. But I did have one really interesting tie from Pomerantz and Rich Boy back all the way to House of Mirth. She opens the essay with a long description about how different men wear different shoes, and what these shoes say about them. She learns how to define them very visually, how to categorize them based solely on what she sees and by how they dress. Their physical appearance displays not only their wealth, but really how they came by their wealth as well, and where that wealth was going. This all made me flash back to Lily Bart and her constant submission to the male gaze.
Men were always looking at her, observing her beauty as a way to determine her worth. It's strange-- this idea of a gaze happens not only amongst the rich (or those trying to seem rich, in Lily's case) that seek to categorize each other, but also in the poor observing the rich. And, I suppose, in the case of the Corey family judging the Lapham's dress and architectural style, the old rich observing the new rich. And in Beans of Egypt, Maine, the middle-class observing the poor.
There seems to be this running theme of the gaze in these novels, in a real fixation on details of dress and style-- to determine wealth, or even to try to discern character. It comes into an interesting contrast with our similar theme of social immobility, that no matter how well you dress, you can't assimilate into the mannerisms and cultural understandings of the upper class.
Regardless, it lends a really interesting backstory to Ms. Pomerantz herself, though. From shoe-shiner to novelist? Just a rags-to-riches story in herself.