When the photographer leaves the shot to answer the telephone, the boy presses a button on his watch, at which point "Don't Stop The Rock" by Freestyle begins to play.
Towards the end of the advert, the girl begins to release air from a pink balloon in time with the music, producing effects similar to scratching a vinyl record.
[1] It has been reported on in numerous news media and blogs and resulted in many people doing eyebrow dances in YouTube videos and parodied in television programmes including The Sunday Night Project, with Lily Allen playing the part of the boy, while puppet doppelgängers of Wayne Rooney and Sven-Göran Eriksson did their version on an episode of Setanta Sports' Special 1 TV.
The Daily Telegraph newspaper reported: "The one-minute film for Cadbury's Dairy Milk chocolate is thought to have been viewed more than four million times on YouTube and similar sites in its first three weeks.
It is twice the number of viewings racked up at the same stage by the firm's previous cult clip, in which a gorilla plays drums to Phil Collins' "In the Air Tonight".