Now that he’s got it in a computer, it might be interesting to ask questions like: what’s the geometry that has the sharpest transition, while also preserving some sort of “good view” of the two subjects from a lot of viewing angles. I think this is not even a good phrasing of the problem yet, but phrasing the problem well is part of the fun.

I guess this could be interestingly image-dependent. In particular she’s quite pale, so I wonder how many surfaces could be shared between the two images.