I could see a really pedantic angle with Sugar Riot that she's a Pictomancer working in a specific medium. Pictomancy is a school of magic powered by imagination, so there is a case to be made that she's actually picturing these realistic forms and landscapes, but her art medium wouldn't normally permit realism; graffiti art like that has to be quick, stylized and often bright to even be seen, even if you're depicting something that isn't.
This is spitballing a possible explanation more than anything, though; it would've been a lot of fun to get more garish and stylized landscapes, and it is a bit disappointing that we didn't.
EDIT: It's possible that we've got a game design thing going, though. Sugar Riot's fight requires being able to quickly identify something like a river, so hyper-stylizing the water might actually make the fight unnecessarily harder to understand.