Museum Narrator

A disembodied, authoritative voice piping up whenever Fry and company wander past an exhibit, dryly narrating the oddities of 20th-century life for 31st-century onlookers. He never appears in the flesh, only in that flat, informational drone museums use to make the mundane sound momentous.

The joke is entirely in the mismatch: Billy West delivers dusty, matter-of-fact museum-documentary cadence over descriptions of things the audience finds ordinary and the future finds bizarre. It's a tiny bit of world-building disguised as filler, and West's straight-faced delivery sells the gag without ever winking at it.