If I understood it correctly, you wanted the icons to sit properly on the shelf lines.
With iOS 7, by default parallax is turned on which renders a depth of field concept on the Home Screen - which requires the OS to sort of enlarge/distort the wallpaper from it's original dimension on the screen.
If you want the wallpaper to fit perfectly like pre-iOS 7, you will have to turn off parallax, Settings->General->Accessibility->Reduce Motion.