I am using chrome on a Mac Retina Display, the avatar image under the answers/questions is using a 32x32 image resolution, which makes the image looks ugly on retina display screens.
I don't see the problem anywhere else on the website (all the other avatars I have in different places use 2x the size and rescale.
I am using gravatar for my profile image/avatar
These questions reference the same topic:
But the retina display is implemented (these posts are many years old), this is a bug in the implementation (that they missed this one).