This house is really amazing, but this bathroom is a little much: https://www.oldhousedreams.com/2012/03/29/1960-lambertville-nj/ (Last sold in 2015 for $630K: https://www.longandfoster.com/homes-for-sale/315-Goat-Hill-Road-Lambertville-NJ-08530-250220020)
I’ve seen this before…its a wet bathroom, which means it’s water sealed with sealed electrical outlets and extra drainage. You can take a hose to the entire bathroom to clean it. That’s why there’s no shower curtain, since it isn’t needed. It’s kinda overboard, but people with money seem to like them.
I don’t really see it as overboard. People in Japan (and elsewhere) have wet rooms. I’m a fan of them, cleaning is easier and additional protection from flooding. It’s the exact opposite of carpet in the bathroom.
I’ve never seen one with this texture before. It’s always been tiles when I saw them.