Releasing the photos was necessary for the Iraqi people to see proof. We cannot expect every society to have the same cultural taboos that we do...while the photos are gruesome and unnecessary for us to see, they are on par for the type of stuff that has been shown on Al Jazzera in the past.
Here is a quote from an Iraqi interpreter who was at the press briefing yesterday when told that the photos would not be released:
"...we are all hanging on the edge of our seats waiting for one single picture, definitive proof. It is so easy, all it takes is to show us the friggin’ corpses...All I care about is knowing, seeing, being 100% doubt free and that press conference proved nothing. An Iraqi journalist stopped me at the door of that hall and asked me whether I am American media (this happens from hanging around NY Times people too much), I told him I wasn’t but I could put him in touch, he said he was a journalist with IMN (Iraqi Media Network, the coalition sponsored media tool) he said that he wanted to make sure that the American journalists understand that Iraqis have huge doubts..."
I'd bet that sentiment is why the decision was reversed and the photos released today.
It would not have mattered which news organization was given the photos...they would have all gotten them in the end.