Yes, the QR code is found in the login page when you are accessing Binance in your computer, once scanned by the Binance phone app, your computer web browser then auto logs in for you.
I like that feature since I don't have to enter credentials when logging in to the computer, especially when I have already done the authentication process on my phone.
The idea both of you are trying to implement sounds similar to me, which I think is very handy and I do feel it is secure since only the one with the phone access (yourself the owner of the phone) has already logged in on it and are the one that is pointing the QR reader on the code on the screen.
Can't wait. That should be a good way of adding an ease f use function to hive.