How does the User card work?
I just noticed a new drop-shadow effect on certain Gravatars.
It makes my profile image look a little silly (see for example this answer of mine).
I've also noticed that it's not applied to every Gravatar -- see the profile images of this random question I looked at.
So... what was the rationale behind this drop-shadow? What controls when it appears?
Most importantly, is there a way to turn it off?