Mirrored Avatars?

Ok, I'm wondering how do I have that reflection under an avatar's picture. Almost like a mirrored image, but for your avatar? Sort of like this
http://boundbytradition.proboards.com/index.cgi?board=helpdesk&action=display&thread=373

I don't know how to do something like that, but I think there's a code that you have to put into the CSS Style sheet. So yeah. Thanks for all your help! ^.^"