So I talked to the woman with 8 baskets on a trolley.... In ASDA they do the picking for delivery and click and collect at this and most large stores. There's a covered large area in the car park with what look like left-luggage lockers that customers can collect their orders. Likewise the delivery vans pick up orders from the same lockers. This is common across all of Scotland as there are no warehouses. Products arrive, are unloaded and placed on the shelves, there is only a tiny amount of space for staging the unloaded products but no back room storage as such. She did say they have warehouses in England for delivery.