Cellphones are in prisons everywhere. Visitors and inmates stow them up their asses and they can be bought inside.

https://www.vice.com/en_us/article/zngpz4/prison-phones-that...

This is fairly likely sent from his own phone - WeChat requires you to verify via various forms of 2-factor to log in on a new phone. He also states that it's own phone in the report.

You can look at #PrisonTikTok on... TikTok. You'll see a ton of footage from people in prison.

The management of Chinese prisons is not as chaotic as in the United States.