kernel: Dog on Mailbox (Street Art)

Dog Piss Graffiti
Graffiti & Street Art on North Limestone - Lexington, Ky.
I don't know how to classify this - is it graffiti? Is it street art? Obviously, I'd classify the orange/yellow lettering as graffiti... but the dog urinating on the mailbox seems more like art (though, it being doubtful that the US Postal Service authorized the dog to permanently piss on its box, is it technically graffiti?).  Either way, I thought it was funny.

UPDATE: A bit more was learned of the folk who make this graffiti/public art. They/he/she are Dronex. Check out another of their work here.