What's Going on Here?

I fear that book publishers are in a sinister conspiracy with bookshelf-makers to get us all to buy more furniture. That must be it, or why else would they randomly change the size of a standard paperback? My evidence (sorry for the quality, I took it with my cellphone):



This may be a little hard to tell but the books in the upper right corner (Thomas Haris's Red Dragon) are about a half-inch taller than the other books on the display shelf. And it's not just this title. The last several times I've gone to the bookstore, I've noticed one or two of these larger volumes. They aren't enlarged print, just formatted differently.

Publishers, I do not approve. I can barely fit all the books I own on the shelf, and the only reason I can do so now is that they are all pretty much the same size (the trade paperbacks, at least) which allows me to stack them on their sides and double things up on the shelf. If you start mucking about with the book sizes, I will get annoyed. So let's just nip this in the bud and keep what we've got, mmkay? Thanks!