Dan Moren, writing for Macworld regarding the new object and face detection features in Photos:
People don’t like to feel that their personal and private photos are being pored over, even if “just” by a machine. But these local silos have, at least at the moment, made the feature less useful, because the analysis happens on each device that the new Photos is on. That means even if all the photos on your iPhone are scanned for faces, when you upgrade your Mac to Sierra, the Photos app there doesn’t benefit from the information on your phone—even if they’re all the same photos.
Not only does that seem remarkably inefficient, but it also runs into possible collisions. For example, I store my pictures in iCloud Photo Library: My MacBook Air running Sierra and my iPhone 7 running iOS 10 both have my entire 23,154 photo library synced. And yet, if I look at the People album in iOS 10, it identifies 12 people; my Mac’s People album has only 11. Moreover, the total numbers of photos for each of those people largely differs between the two. For example, my phone identified 523 pictures of me; my Mac, only 306. Those are some pretty disparate numbers, and a search for photos on one is sure to look substantially different from the other. And if I make changes in one place to add in more photos to a certain person, I’m just going to have to repeat that process on my other devices.
Via Michael Tsai, who notes:
It sounds like to have things work the way you’d want, you would have to re-tag all your photos on each device. And, I guess, forget about doing anything with faces from the Web interface.
Apple has previously stated that identified objects and people won’t sync — at least, not initially — for privacy reasons. I was under the impression that iCloud was extremely private and secure — again, this is what Apple has been saying for a while. Like Tsai, I don’t get how storing photos in iCloud is totally private, but it’s not yet possible to securely keep associated metadata in sync, too.
At WWDC this year, Craig Federighi strongly disagreed with the argument that privacy and cloud features are competing interests. I’m inclined to believe him; I don’t think that privacy must be compromised in order to provide services that are proactive or user-tailored. I hope that my belief isn’t too idealistic, but Apple’s argument gets harder to agree with when rudimentary gaps remain in existing features.