Enter your master passphrase. Master Encryption Key is decrypted strictly in RAM.
Enter the master passphrase that was active when was exported. Its items will be decrypted with that passphrase, then re-encrypted under your current vault's key — your own passphrase never changes.
This QR code contains the encrypted item(s) only — nothing is decrypted. Scanning it still requires your vault passphrase to unlock.
Wallet's "Add from photo" option can store this as a generic pass. It asks for a Title and Description — suggested values:
Scan a credential QR code exported from this vault (or another copy of it) — via camera, or from an image saved elsewhere, including Google Wallet.
Locking in 30 seconds due to inactivity.