Bits left in Hammersmith

Someone left an abstract painting, seemingly executed in acrylic, perched upon a carwash / garage window. Perhaps in lieu of payment for a £10 in-and-out?

Okay, so, I can see what some morning-drunk publican has done here. It just doesn’t work with my head somehow.

Is this a warning not to enter Ravenscourt Park? Or is it an example of post-twitter review terminology? Or did I dream it?