The elaborate set of Tativille had its own roads, electrical systems, and (in one of the office buildings) a fully working elevator.
For the restaurant sequence, Jacques Tati had to work out each part and direct each character separately. It took him seven weeks to shoot it. First he'd set up all the different movements in the background, then he'd set up each action in the foreground, looking through the lens while composing each shot so he could see everything at once. He had to shoot it all in sequence.
To cut production cost cardboard cut-outs were used as extras in the background. To give them life some human extras would interact with the cut-outs.