I bet it's because he sent her a customized one of these """"apology"""" drawings from some sock (possibly
this one).
I'm assuming he sent a different one out to each brony he wants to be unblocked by- My god I fucking hope the others post theirs, too, because this one is god damn hilarious. Chris's much-hyped "apology" = telling some brony "Your OC thinks you're an asshole, but it's all OK because he apologized to me on your behalf!! So everything's OK now and you can just unblock me! You're welcome, kthxbye!! [lightning bolt blush emoji lightning bolt]"