We've all done this, because we're so mature. You see a cow on the side of the road, stick your head out the window and go "Mooo!" Like we expect the cow to think, "Hey, there's another cow, driving that car! How can he afford that?"

Shandling’s joke riffs on a familiar bit of childish roadside behavior—mooing at cows—to expose how adults often retain playful, irrational impulses beneath a veneer of “maturity.” The humor comes from pushing the premise to an absurdly logical endpoint: if we moo, we must (on some level) imagine the cow will interpret it as meaningful communication, even mistaking us for a fellow cow. By adding the tag about the cow’s imagined envy—“How can he afford that?”—he satirizes human projection: we attribute our own social concerns (status, money, belonging) to an animal that has no such framework. The line is a compact example of observational comedy turning everyday silliness into commentary on ego and anthropomorphism.