So what are the additional photos and videos Rumsfeld warned about on Friday? Rumsfeld warned there are "a lot more photographs and videos" that haven't yet been seen. "If these are released to the public, obviously it's going to make matters worse."
Here is a possible answer: (From the New Yorker):
NBC News later quoted U.S. military officials as saying that the unreleased photographs showed American soldiers “severely beating an Iraqi prisoner nearly to death, having sex with a female Iraqi prisoner, and ‘acting inappropriately with a dead body.’ The officials said there also was a videotape, apparently shot by U.S. personnel, showing Iraqi guards raping young boys.”