I recently moved a handful of shortcuts to my desktop and was disappointed to see that they lost their icon in the process (they became blank document icons). A google search brought me here where it was suggested that I download repair software or attempt to repair the system icon file manually. The following two solutions were both successful and much simpler:

1) Reassign the shortcut icon. Right click the shortcut and select Properties, go to the Shortcut tab, click on the Change Icon button at the bottom, select the icon, click OK, click Apply.

2) Create a new shortcut. Right click the shortcut and select Open File Location, right click the exe and select Create Shortcut, move that newly created shortcut to the desktop.

I'm not sure why Win 8.1 likes to destroy my shortcut icons when they go to the desktop, but one of these two solutions usually works for me.