If there are any secrets in the mobile phone, it must be important chat records such as SMS, WeChat, QQ, wallets and photo albums, because these things involve our private life, work, family situation, or some shady things. Besides, we don't want these things to be seen by others. If you think my explanation is not clear enough, you can watch the episode "Mysterious Mobile Phone" by local lang, a foreign daughter-in-law, on Guangdong TV station official website (Litchi. com) (Cantonese-speaking friends can watch it by themselves), and maybe you will understand it better.