One of them is scanning on device. The other isn't.

zimpenfish · on Aug 6, 2021

> One of them is scanning on device [...]

                                 [...] when the photo is about to be uploaded to the cloud.  If you don't use iCloud Photos, it won't be scanning your photos.

aaomidi · on Aug 6, 2021

> about to be uploaded to the cloud

it's scanning ON your device. This means Apple now has the capability to scan and find files on your device. Which means they have opened the pandoras box of over-reaching government requests.