I have a somewhat similar experience, except that I’ve concluded that it’s far easier for me to remember a 2d image than physical 3d representation. My hypothesis is that a flat 2d image is just far less information, and doesn’t vary based on the angle I look at it, so it focuses attention. It’s also something I can reinforce by looking at again, even in thumbnail form. I’m not great at remembering faces, but remembering pictures of faces is super easy. ¯\_(ツ)_/¯

I’ve concluded it’s not (very) related to the extra attention required when taking a photo is that I can often remember photos of people that I didn’t take - e.g. their facebook profile photos.