What we saw [in the Abu Ghraib photos] was indeed shocking. But we were emphatically told by the administration that none of this was policy, that all of it was dreamed up by some nutjobs on the night shift who got their ideas from bad television or their own demented psyches. When some of us pointed out that there was clear evidence that some of these techniques were authorized, that, indeed, the commander of Guantanamo Bay had been sent to Abu Ghraib to "Gitmoize" it, we were told we were slandering the troops and the administration.
One great merit of the Schmidt report—which is otherwise riddled with worrying euphemisms, dismissal of troubling facts, exoneration of almost all commanders—is that we now know that almost every one of the Abu Ghraib techniques was practised and innovated at Guantanamo. These were not improvised out of nowhere. They were what the report calls "the creative application of authorized interrogation techniques," and the interrogators "believed they were acting within existing guidance."
Marty Lederman has more analysis here.