> Ditto for pictures of Winnie the Pooh.
References to Winnie the Pooh in these discussions are about China, where images of Winnie are deemed to be coded political messages and are censored.
The concern is that Apple are building a system that is ostensibly about CSAM, and that some countries such as China will then leverage their power to force Apple to include whatever political imagery in the database as well. Giving the government there the ability to home in on who is passing around those kinds of images in quantity.
If that seems a long way indeed from CSAM, consider something more likely to fit under that heading by local government standards. There's a country today, you may have heard of, one the USA is busy evacuating its personnel from to leave the population to an awful fate, where "female teenagers in a secret school not wearing a burqa" may be deemed by the new authorities to be sexually titillating, inappropriate and illegal, and if they find out who is sharing those images, punishments are much worse than mere prison. Sadly there are a plethora of countries that are very controlling of females of all ages.