With Blippa, it is easy to create QR business cards: In Labelsadmin, goto Marketplace and copy the Business Card sample to your account (make sure to select Include Labels and QR designs).
With this comes a pre-made label, QR Business Card (with image).
Make that default for your business cards by the QR design settings in the template.
If you want to do this manually, in the label editor, select Add image from URL and use this as the url: $var:staff.image-url$
This will show as File not found in the editor but will render ok on each label.
