Staying hydrated
Now, I know that sometimes different countries can have different traditions, and different accepted norms when it comes to bathrooms. In some countries, a bidet is a requirement, and in others, it’s looked at as a little bit weird.
It is possible that this bathroom has had visitors who’d never seen a urinal before, and so thought that it was a water fountain. But surely the smell alone would have put them off? That would have been the first clue that I wouldn’t find drinking water here.