Doesn't spoil anything, but doesn't make much sense unless you've read the book.
In short, there's a bit about a symbol that looks like an eye in a triangle, and this is where my mind went.
To Harry's credit, he's not as shouty and obsessive as he was a few books ago. But I still think he would have done this if Yugi had showed up mid-book.
(His glasses, um, fell off when he jumped at Yugi. Eheh.)
This picture can be found somewhere in the middle of Harry Potter Funnies