I use Google Photos as my photos app. I used to backup photos from another Android device when it was free to back up in reduced quality. I have noticed that some features (eg: Memories, face grouping, photo date editing) are only available for backed up photos, and not local ones. Is there a way to enable those features for local photos in Google Photos?
A modern Pixel phone could probably run the AI models locally but they would likely be more limited and it wouldn’t be particularly battery-friendly.
An old iPod touch wouldn’t be able to so I think it’s safe to assume those functions were happening on Apple’s servers.
In fact I would be confident claiming that no mobile devices are currently running these models locally, whether you are using Google, Apple, or some other photo app.
Like I said, it may be possible for some modern devices with TPU chips to run them locally but that is not happening currently and would probably not be as good as experience if they were
This is exactly why I was motivated to start using Immich instead. Using any of these corporate services you are giving away your privacy for convenience.