All orders are directed to a central portal available on tablets around the venue. The orders will appear in order of time to be approved by a member of staff and processed through PoS.
The staff member can amend the order prior to approval eg. if the venue has ran out of an item they can inform the customer and change it before the card is charged.
Venues can decide where to place the tablet(s). Usually this is located beside the PoS stations.