Icon examples.
It's meant to be "shadow" strong and basically either make your character look ridiculously badass or sexy as hell.

[url=http://www.furaffinity.net/journal/5307799/]Check my journal for info![/url]

Art + Veldt (left) by Me.
Zenuel belongs to himself. (and to his bby)
Zero belongs to PhantomStar - http://www.furaffinity.net/user/PhantomStar/
Bottom 3 belongs to machineboy - http://www.furaffinity.net/user/machineboy/ (last icon is animated, although not shown here)