The response was posted by the original reporter. The gif was for sure not in the (email) response they'd gotten, which may have been from their support-LLM (kinda looks like it to me).

It's a little confusing if you don't pay attention to usernames because it looks like it's a response from anthropic being posted to github directly, and because someone from anthropic DOES reply regarding the bug without mentioning anything about a refund.

I think the gif was a sarcastic addition from the user pasting an e-mail he received into the comments.