>>8307146Jokes don't necessarily have a setup and a punchline. Those are just the classic jokes. One can joke by being ironic or facetious and no set-up or punchline is required, just context.
Likewise here, in the context that you're reading a serious book, the fact that the author sort of breaks this seriousness and shows a little of his own personality in an otherwise formal text is unexpected, and being caught off guard is one of the key elements of a joke.
As for the joke itself, the author makes a remark on the more vulgar aspects of a commonly thought of as 'good' job. Aspects that were in the past considered unacceptable and then suddenly became acceptable but we still sort of willfully ignore. For example, many famous models will no longer do nude shoots, but have done them in the past in order to climb the ladder, and often don't want to talk about this fact or try to sweep this fact under the rug. Others will do nude shoots in the name of "art", denying that there is anything very sexual to the pictures, and if you think that they ARE sexual, then you must be the pervert. They're shifting the emotional burden to the observer in a fit of cognitive dissonance.
tl;dr: it's a mildly funny joke you fucking autist
