The QR code you find in the Inceptor box authorizes your Father.IO account to use the Inceptor, regardless of which phone you are using or which Inceptor you are using, because the QR code authorizes your account (email & password/facebook).
The original QR Code that comes in the box with the Inceptor is a first-time use code. You only need this QR Code to activate your personal account the very first time. If any other account scans this QR Code, the procedure would give it permanent access for trying to pair with any other nearby available Inceptor device.
Once the original QR code has been scanned and used, it is automatically cancelled and cannot be used a second time. If you have any issues related to the scan of the original QR code you can revert to firstname.lastname@example.org.