I would use this for a live photography event like Santa photos. Customers would fill out a form. The workflow would create a QR code with customizable info like the client ID and email, save the file to media storage, and send the URL to a custom field.

The user would be directed to a webpage with the QR code for the photographer to photograph before taking the Santa photos.

(Plugins for Lightroom can read the QR code and copy it to the photos' metadata following the QR code. I've been using a paper system, but it would be great to have this work seamlessly.)