It has been stated that it’s not a true 1:1 hash. People aren’t thinking about that. It’s been stated it will detect crops, color adjustments, warps, transforms, rotations and more. Therefore, it’s not a true hash comparison 1:1. So how can they guarantee a similar photo with an adult won’t get flagged? What if that 24 year old looks like 15? What happens then? I know many people that look like they are in their teens. Even under manual review that can possibly be an issue. This isn’t as simple has hash match if they also can tell you manipulated the picture, which would produce a different hash but they still will match it.
Hash maps are huge! The likely hood of it matching a false positive is astronomical, then you have a threshold as well.