Stuff whose sole purpose is to be pleasing to the eye. More than just "good looking"; adding EyeCandy requires extra effort that does not add to functionality.

For example, even a basic WindowManager can look nice, but that doesn't qualify as EyeCandy. Things that do are, for example, titlebar transparency support or extra animations.

Sort of like the blonde girls you see on TV in the pits at motorsport events? --JohnMcPherson

In the sense that they're just there to be sexy, yes. :) --AristotlePagaltzis