>>> Only images that match the hashes of the database of CSAM held by the National Center for Missing and Exploited Children (NCMEC) that are uploaded to iCloud Photos are checked.
Incorrect. All files on the phone will be checked against a hash database before being uploaded to iCloud. Any time before, which means all the time, if you have iCloud enabled.
All files on the phone will be checked against a hash database before being uploaded to iCloud.
A cryptographic safety voucher is created for each photo as they're uploaded. The iPhone doesn't know wether or not anything matched. Nothing happens unless the user reaches a threshold of 30 CSAM images that have been uploaded to iCloud Photos.
The phone also doesn't know whether something is about to be uploaded or not. Therefore, all files on the phone will be checked is the relevant portion of that sentence.
Incorrect. All files on the phone will be checked against a hash database before being uploaded to iCloud. Any time before, which means all the time, if you have iCloud enabled.