Here's a clip from Wim Wenders' Tokyo-Ga, a 1985 documentary about a visit to Tokyo. He films a regular day of business at a fake food factory, where workers assemble foods from warm wax ingredients. Off camera, they break to eat their own lunch among all the works in wax.
Wenders left the environmental sound in, with minimal narration.
"The wax must be kept warm all the while. Other than that, the preparation of a wax sandwich is not at all unlike the preparation of a real one."