Presuming that is what they're doing, it won't stay that way for long. It's absurdly easy to change the hash of a file. In the case of something like JPEG, yo

Presuming that is what they're doing, it won't stay that way for long. It's absurdly easy to change the hash of a file. In the case of something like JPEG, you don't even have to change the file itself, you can just change the metadata. Apple could presumably only hash the image itself, but again, all you have to do is make tiny, imperceptible to humans changes to the image and the hash is totally different. Long story short, this is either nearly pointless and privacy invasive, or it's about to get drastically more invasive to be effective.