Mother in Commercial

Mom appears first the way the show wants you to underestimate her: a beaming, apron-clad spokeswoman selling robot oil and appliances in a chipper old-timey commercial. She calls everyone "sweetie," beams at the camera, and radiates the folksy warmth of a beloved grandmother pitching wholesome products to a trusting public.

The joke is entirely in the gap between the performance and the truth: Tress MacNeille plays the commercial persona completely straight, all honeyed sweetness and daytime-TV cheer, which makes the character's actual ruthlessness as a monopolist industrialist land harder later. It's a small, perfect piece of comic misdirection.