He put it there leveraging a whole urinal factory. Transported into today's world, instead of clicking "generate" on a prompt with "urinal" on it he put "urinal" in the amazon search box, picked the first result, and then hit "buy".
The art is in the idea, the message, the thought or impression that's getting transmitted, the effect in the recipient's mind (in this case it was a shitpost to troll conservatives on the one side and have a good chuckle among people who got it on the other). The rest is craft. Craft, on its own, can be fucking impressive but it's not art.
And, of course, yes, not everyone hitting "generate" is putting a urinal on a pedestal. Much of the AI stuff out there is devoid of artistic intent, much of it isn't even crafty, but that doesn't mean that something being AI generated cannot be art, or that it would need craftiness to become art.
In the case of his bicycle wheel thing he went through a gazillion wheels -- hitting generate a million times if you want -- until he found one that was neither beautiful, nor ugly, but one that was profoundly uninteresting, "just a wheel, nothing special". That was work, the actual work of an artist (judging the impression something makes), and with precise artistic intent -- to make a statement about how art should be about engaging the mind, be not about aesthetics.
The people producing profoundly uninteresting works with AI don't do that. Just goes on to show that the author is very much not dead.