I don’t see what distinction you’re trying to draw here. It previously had trouble generating full glasses of wine, they made some changes, now it can. As a result, AIs are capable of generating an image of a full wine glass.

This is just another goalpost that’s been blown past, like the “AI will never be able to draw hands correctly” thing that was so popular back in the day. Now AIs are quite good at drawing hands, and so new “but they can’t do X!” Standards have been invented. I see no fundamental reason why any of those standards won’t ultimately be surpassed.