They're talking about TV shows and anime, but that very specific definition of "filler" sounds like "Man, what's with all these side-quests in this video game that have nothing to do with the main quest? Get that shit out of here."
(Also, another "out of pocket" misuse in this clip. And this one was uniquely strange. "'Out of pocket' is the correct term to describe that move." No, it's not, and it's exceedingly strange to hear someone say that it is, at least to me.)