I think Bourdieu (a famously obscure French "postmodern" writer) is basically saying that class can physically manifest itself in the body, and that taste is fundamentally a class value. It's from a book that I didn't read(!) called Distinction: A Social Critique of the Judgement of Taste which is supposedly about how distinguishing your taste is a form of distinguishing your class. For me this idea is important because it leads to today's liberal aesthetics of posturing while doing nothing in practice.

In general my point with the comic is that even if we take it at face value (poor people make bad clothing decisions and are therefore immoral and stupid), then poor people only do this because of proletarian culture, which today is obviously co-opted by consumer society from its inception, even created to be simply a target market, sold to and commodified; therefore it is not immoral or stupid at all to fit in with your peers, it could be socially mandated. Of course, the comic is dumb and Bourdieu's idea becomes confusing and breaks down when all the bougie elites read his book and decide that understanding proletarian culture is also a form of upper class distinction (which fits right in with liberal multiculturalism) but I think the idea is still very helpful.