The calculator actually calculates
The lock screen
You can put a calculator on the home screen. It adds and subtracts. Type your passcode on the keypad and the vault opens. If the calculator were a fake keypad with no maths, anyone who tried 2 + 2 would know.
Selecting photos
Tap Select, then drag across the grid. Same gesture as Photos. A vault that invents a new way to pick twelve pictures is just slower.
Wi-Fi Share
Scan a QR code and the photos open in a browser on the same network. Thumbnails show up first. Full size follows. The session code dies with the session, and the photos don't go out over the internet.