They’re not saying they want juice coming out of an ass when they call an ass juicy… It’s meant to describe something that looks appetizing, like a juicy grape…

And that ass is very defined/toned, I would not classify that as an “absolutely normal ass.” I don’t think it’s thicc, per se, but it is a very attractive butt (and I say that as a straight guy). I do agree “thicc” is highly overused, as it should be describing something that is actually a bit fatty/curvy/voluptuous, versus an athletically toned piece of anatomy.