Well, as I said, there could be a feature where you can view the full picture when you click it, as in optional, but not automatically when the page loads because it's disturbing.
Let me show you what I'm talking about...
It says "The picture has been resized to fit. Please click on it to view its full size".
That's what you see when you click it (of course that depends on the image's original size, so the Desktop pictures will definitely be bigger than that)...
It says "Click on it again to fit the screen" which makes it small again.
I think it's a good idea for this forum, especially when viewing threads like Desktop Pictures.