What would the purpose be for manipulating a photo in this case? I just dont see anything positive that can come from that move. Getting as much information out to the public is the most important thing right now. If they have the ability to identify the car in greater detail they would do so. If they knew LS was in the car they have no reason not to mention it unless they are 100% positive that she is dead and are basically only investigating the crime and not her whereabouts. While I think that this is unfortunately the most likely scenario, they still have to hope this is an abduction and someone is holding her against her will and, thus, proceed as quickly as possible.
I wouldn't want to whole world to have a photo of my daughter being held against her will in the back of a truck, if that is what the photo is as many people have believed it could be (Lauren, not my daughter). Maybe that's just me.