Have them do a fake behind the scenes kind a thing on the set.
Show us their "off screen" personalities but have them exaggerated.
Such as: Jerry is highly emotional and pompous. Hard to work with. George is the mastermind behind the show. Writes, Edits, sets the lighting, etc. Kramer is identical person. He doesn't act that way. He is that way in real life.
Start the Episode with them wrapping for the day on a shoot in Jerry's apartment. Jerry delivers a punchline and the director yells, "cut".
But how should Elaine be in real life??
Herb