Condition exemplified by a favourable outsourcing race whereby the head wobbles about like a bladder on a stick when making conversation.
Wadder Wadder = sound of language used.
Thunderbird = body language movement used (like a Thunderbirds puppet).
Joy said to her friend "hey look, that man is demonstrating the wadder wadder thunderbird movement we talked about" in that restaurant.
Imagine moving your head from left to right and chanting 'no,no,no,no,no, balti' while at the same time suspending your arms in the air like a puppet.