WhySoSerious.com has been updated to show all of the letters that we pointed out earlier today.
Now, there’s another hidden trick. If you click on the right hand side of the picture, along the Xacto knife, you’ll get a new screen, with a challenge from the Joker.

I wonder what the prizes could be this time around?
UPDATE: The WhySoSerious site shows a new image of The Joker, shown below. Also, the challenge note above is located on a new website - RorysDeathKiss.com.