I'm not sure how feasible this is, but it would be cool if photos had tags depending on what entity is present in the photo. For example, if you took a photo of a pig in a desert, the photo's tags could be "Entity: Pig, Biome: Desert". With this feature, a server could setup some sort of quest system where players have to trade a picture with specific contents for a prize. Alternatively, this could be something a new villager job could handle (a photographer villager?). Other possible tags could include weather, time of day, or players?

Anyways, that's about it for my suggestion. I really like this mod and had Pokemon Snap on the mind.

All data that you mentioned is saved in the photograph.