Len Testa says the second half of the first pre-show is different depending on which room you're in (or may just be randomized.) That may explain the part where he says "oh, hang on" and goes away for a minute and comes back in the preshow. It's loading the randomized next segment.
Little things like that make the whole Pandora experience great for visiting multiple times, and that terrible pre-show (somewhat) more re-watchable.