Where did you get the cover from? Did you scan this yourself?
A couple of problems I notice:
You've got the resolution set to 72 pixels/in. It's surely much higher than that—1200 ppi, maybe. This is a problem for anything trying to display the cover art actual size. (I believe the guidelines also suggest uploading at 300ppi, I personally feel 600ppi is sometimes warranted, but 1200 probably never is).
It honestly looks like you took a JPEG and upscaled it. You've got magnified jpeg artifacts, and in general the whole picture looks like pixels have been duplicated. If you've done that, please don't—at best it just wastes disk space.
If this is something you scanned, you need to scan at the resolution you want to upload at or higher. Do not upscale! And if your scanner has JPEG compression, you should probably turn that off.
Also, beware that scanners have optical resolution limits—typically far lower than the maximum resolution the scanner software lets you pick. The only practical way around the scanner's optical resolution limits is to buy a better scanner.