We have heard some reports that in the camps, people who do not acquiesce to the re-education curriculum or to the struggle sessions they're subjected to—where they have to stand in front of others and denounce their past crimes, such as studying the Quran, learning Arabic, travelling abroad, or whatever their supposed crime is—or who do not submit or perform those tasks well are often subject to punishment. It includes isolation, being placed in stress positions, beatings, or being forced to eat pork, which is a major religious violation for Uighurs.
There are other psychological violations, such as things that target their manhood or masculinity, or a denouncing of their parents. All of these sorts of things try to trigger certain responses in the detainee and break them in some way.
It's not unique to the Chinese case; there are other governments. The U.S. government has done similar things to detainees in other situations, but it's still quite horrific, especially because these people have not really committed any sort of crime and by any international standard should not be considered extremists or terrorists in any way.