One wonders if he drew this partly to prove he can draw more than one body type.

This is a prototypical version of the “Existence of X implies the existence of Y” joke (“The existence of casual sex implies the existence of ranked competitive sex”). It doesn’t land quite as well in that the punchline comes when you figure out what the premise is, but the same reasoning is there.

And they killed most of their Jewish population! Wait…

This sounds like subtitles for a DVD commentary track, which were probably supposed to be a separate subtitle track but weren’t for some reason (or your player defaulted to them alphabetically).