Between finishing an item and handing it back, it gets packed and put somewhere. Those two steps now leave a record.
Package Counts and Review
Enter how many packages an order became and review them before moving on, which catches a miscount while the items are still in front of you.
Scanning That Confirms Itself
The scanner plays a sound on a successful read, so staff know it registered without stopping to check the screen.
Where It Was Put
Recording the storage location means finding an order later is a lookup rather than a search of the whole rack.