I think a better question is “what do the nudes you like look like?”
Like, if you’re a straight male you’re never going to be turned on by your own nudes but I know for the majority of straight men they aren’t looking at just closeups of vaginas or boobs. Translate that to the male body.
Sending nudes is an artform- it can be arabesque, or grotesque. It can be of looks, or “truth”. It can be of aesthetics, or enlighten one on what “it” is. Regardless of what it is, it is a form of art- the exposé of the hidden.