Why?

Does he really think this is going to keep his ass safe? The bigger question might be why the dude decided to leave his artwork behind. Is he that proud of his creation? At least he flushed, unlike the dude who used the adjoining stall. That one was ripe. Sadly, this is the closest john to my office, one that I am forced to share with the unwashed public, and I use that term loosely, as the sinks here double as foot-washing fixtures. (I know, certain cultures place great value on regular foot washing, but it doesn't please me to see a man with one foot in the sink, soon to be followed by the other).
And then there's the spitting. The sinks are often coated in it. No one flushes the urinals and the toilets are often not flushed, so it usually stinks. There is always toilet paper on the floors. Many men seem to prefer peeing in the privacy of a stall, and I have yet to encounter a single man in this bathroom who has the courtesy to lift the seat. As a result, the seats are usually covered in piss.
Naturally, I normally travel to a different floor to use a bathroom. What I really want to do is post a Bathroom Etiquette sign. Even the staff bathroom on a different floor has sign above the urinal asked the men to flush after use. If you have to ask staff to do this, you have a problem. Public washrooms are disgusting, but you didn't need me to tell you that, did you?