I think I've posted about it here before, but the shirt combo is Talking About the Abstraction. It's a tee with this removable...thing that is screen printed with patchwork madras. It's asymmetrical and sort of weird.
It has nothing to do with post count, just the quality of the fits, criticism, and advice. There are some fantastic posters with lower post counts who obviously know what they are talking about and consistently post inspiring fits (eg. Platypus), as well as members with high post counts who consistently post poor fits and add very little in the way of constructive criticism. But lackluster fits and comments will be criticized, hopefully for the sake of inspiring improvement, regardless of post count. If someone posts a poor or experimental fit they should expect criticism, again, regardless of post count.