> Once the images and tokens are uploaded to iCloud photos, iCloud will alert if 30+ of those security tokens show a match, it will alert Apple's team, and they will get access to only those 30+ photos. They will manually review those photos, and if they then discover that you are indeed hoarding known child pornography then they report you to the authorities.

Apple: We have 29 matches on your device of "known CSAM"[0]. However, despite our confidence level being very high, we won't report it to the authorities because we value your privacy!

[0] for varying definitions of 'known CSAM'.