Something I saw in Milan

Boys, I passed an Aprilia billboard on my way to Linate airport, but unfortuately it happened too fast for a photo. The image was thus:

A wall, with two guys. One guy is standing with his back to the viewer, obviously pissing on the wall. The other guy is straddling his red Aprilia, and somehow contorting his body to also piss on the wall!

What the?! How would that work in real life?