I don't think I get it...
But that no surprise since I don't get jokes much often and I need a round of explanation until I finally get the joke and say "ohhhhhhhhhh, I get it!"
It's a scene from Twilight where I guess the chick asks the Vampire his age, it's then changed to say 12 (pretty sure Ash is 10 though) and Ash from the Pokemon anime's face is covering the Vampire's. The joke is that for the 10 or so years the Pokemon anime has been running Ash has always remained the same age.