Precisely the same difference. They are both professionals. You or I, as amateurs, would take the first million and then scram; go off and breed cocker spaniels or fix up vintage cars instead. Anyway, do whatever we really wanted to do, a full-time hobby, if you will.
He doesn't work for the money, the money is irrelevant. He works because it's His job. You're right, He doesn't need to work. He works because that is what He does.