I saw similar in the Forbidden City. One of the reasons I vacation often in Vegas is the huge number of clean public restrooms.
That’s where I saw it for the first time. Kid went right on a carving. It’s kind of hard to explain, but if you’ve been there you've seen the carvings next to stairs.
It’s becoming less common as diapers have been used, but still in use. The weirdest is parents who use diapers on kids wearing these pants. Might be easier to change the diaper I guess.