Kids wear superman pyjamas to be like a superhero. Superman wears Tim Cahill pyjamas - ergo Tim Cahill is a superhero to Superman.
I'm no Everton fan but a huge Cahill fan - bargain of the century. I may concede that the banner itself may not be comedy gold - I've had a slow evening.
Ah! I think it was the pyjamas bit that threw me; wearing a cape, and your pants on the outside of your tights.....then I would have understood.