Mostly face detection. Possibly some color correction. I don’t think this is unavoidable at all.
Even then, with the loads of publicly available free photos on the net, I don’t see a reason it couldn’t be implemented with Free Software.
The only issue may be the one where we don’t know how to distribute training data in human-understandable form, letting flooding the user with lifetimes of information, which kind of defeats the point. But understanding “finished” neural networks is an active area of research, so it’s not certain yet.