It opens the bag's page at /bags/<bag number> (you must be logged in as an admin, or as the customer who owns the order). The page shows Pickup or Delivery, the delivery date, the order number, the customer's name, the bag's pickup location (name and address) or the delivery address and gate code, any delivery notes, and the list of items in the bag grouped by ordering type with quantities. Admins see Mark Bag Delivered / Mark Bag Returned buttons (when enabled in settings) and per-item Mark Packed buttons (subject to the settings below), the customer's Unreturned Bags with their own status buttons, and the customer's Upcoming Deliveries with a Load More button.