I am doing a two-day visit to Pairi Daiza next week, so at least I know I have to truly look everywhere for exhibits and theming, bathrooms included.
The fact that they invest in these kinds of displays even for bathrooms (at least for the gents) is I guess more proof that Pairi Daiza is truly next level and in a league of its own when it comes to theming. Although I guess having fish, frogs of lizards near the bathroom is more relaxing and less excessive than some of the other stuff at Pairi Daiza...