"Se non è vero è ben trovato" but this reddit post [1] does a decent enough job of explaining what's happening there (or what cool people think it might be happening in there). Slightly NSFW text post:
It is, and that's what it's intended as. Some shows in the US do it too. e.g. Lane 8's This Never Happened shows in Oakland. But the most recent version of that had a lot of people complaining that there were lots of phone camera usage, so the sticker thing might not work in some venues.