Graffiti weirdness

The huge graffiti mural on the wall of a small car park near the office, has been painted over with this.

Even stranger, one day last week (when I didn't have my camera), it had been subtly changed to read "Just look at tits". I planned to take a photo of it the following day, but found it had returned to "Just look at this". As yet I can't work out whether I just imagined it (which would imply some deep Freudian issues, I'm sure - particularly since I was so astonished by it, that I had to check my iPhone for this camera).
I'm just waiting for it to change back again...