Click HERE, then on the "play" button and watch. The bit with Stan is about 3/4 of the way through.
If you don't want to wait, Stan shows the guys an old Fantastic Four comic book. Where he and a co-creator Jack Kirby, drew themselves into the comic; at the point where Mr. Fantastic and Sue Storm are getting married--but they get kicked out as wedding crashers. Basically, they are doing the same thing for real in the live action movie. Unfortunately, the interviewer never asks the obvious question. Who's playing the part of deceased Kirby?