It's a modified version of the automat. Customers can walk around and see the options, then go to an ordering kiosk and place the order. The next generation of this will probably include a "shopping guide" bar code scanner that orders each item as the customer selects it. When you press "done shopping" the order to goes to a "picker" who walks around the back rooms putting the entire order into bags, placing the completed order on a conveyor, and moving the merchandise to the checkout location.
Very little if any human interaction, so minimal opportunity for fights or riots. Just be careful coming in and out of the employee access door to the back rooms.