If I remember correctly, he kinda did the whole intro to You Must Remember This almost verbatim, down to the "Won't you join me" line, except of course for the things that specifically refer to You Must Remember This.
Isn't this show's intro the one Tom mocked/imitated when he talked about joining the Panoply network?
I thought that was Welcome to Night Vale.
This HAD to be a reference to Karina's podcast -- it was 100% verbatim, and he even "did" her voice. 100% agreed.
I also love You Must Remember This, even the times Karina goes into her somewhat ridiculous voices and hyperpronunciations. Incredibly informative and entertaining.