Offer relative position in 3D-space between two or more images
If I take two photos of a subject, I would love to be able to know where the second photo was taken in real space relative to the first. In the example of handheld smartphone photography, if the first image is a baseline then I would love to know the xyz offset of the second image. Even if I believe that I'm holding a smartphone in the same position without moving it, it's likely moving at least an inch in multiple dimensions just due to hand shake. However, I might also take a side profile and it would be just as useful to know the positions in that scenario.
The super deluxe version of this request is a multi-camera bundle adjustment where I could plausibly take an arbitrary number of photos from different positions around a subject and use the API to reconstruct a 3D spacial map of each camera based on how they see each other using bundle adjustment or similar.