When I tried The Impossible Instant Lab, I used the corresponding iOS app to choose the digital images I wanted to create instant photos from as well as the exposure time for the instant film material I used.
The app let’s me create analog images with the instant lab, which basically is just a housing case for the instant film cartridge and the iPhone while exposing and is manually operated.
But the app also works the other way around. It features a scanner functionality, so one can digitise the instant photos to save them in a digital picture gallery.
One just takes a picture from an angle with no reflections from the instant photo’s surface and selects the corners of the picture’s frame in order to cut and straighten the image to right format. Since The Impossible Project offers film material for the Polaroid 600 & SX-70 series as well as Spectra the app can be adjusted to the correct setting.
I am not sure why anyone would need this feature, but it is a nice gimmick. It somewhat foils the purpose of The Impossible Project and does not provide any decent results but still, it is an easy way to keep a digital memory of your analog instant photos.