I was there a few weeks ago to see if I could alleviate my growing apathy and misanthropy through its spectacular architecture and artworks. I used the tram every day and didn't have a clue about the mask enforcement. Most people weren't wearing them but I did laugh at the sight of a few of the teenagers who were masked up. I just assumed they were your typical 'woke' kids.
I didn't find out about it until the last day when an obese and semi-retarded pensioner who was desperate for any form of human interaction told my girlfriend about the policy. Apparently, police would occasionally jump on and lecture a few people (usually kids) but it seemed like no one really took it seriously, aside from old folks.