IIRC, the Qantas briefing uses the words "It is a Qantas requirement ..." The emphasis reflects that in the video soundtrack.
True... but I've never understood why it hasn't become aviation LAW for more emphasis (like smoking).
Also, I've never understood why the food carts aren't make of something lighter, like carbon fibre or some kind of hard wearing plastic, with much rounder edges (this would also help prevent the guillotine effect as the carts are being pushed down the aisles and you happen to have an arm hanging over the armrest or a leg dangling in the aisle).