It's wallpaper that looks like stacks of books. Which is such a fun idea. But then I started thinking about it and in the end, if I have a little bit of extra wall space, I'm going to put a bookcase there, not pictures of books. And I wouldn't want to put that wallpaper up somewhere that it would get covered, because it's just too cool.
So as fun as the idea is, I think I would prefer stacks of books I can actually read.