>>47760513Shinx's design didn't change; Vulpix is making fun of Shinx (a boy) for his fur pattern on his hind legs that's similar to the "black stockings" look that Braixen has. Shinx brings up "modern aesthetics" because Shinx's back fur pattern was never though of as stockings back in Gen 4, but Braixen's fur pattern was immediately seen as stockings in Gen 6.
Sorry if I ruined the joke by trying to explain it.