I understand what you and others are saying and would be tempted to agree with you, but still take issue with shielding from the truth. It is the killers who made what is in the pics and that is truth. Does it traumatize the children? Maybe and just maybe not, but let me tell you about my wife.
We as parents naturally want to protect our children from harm and evil, but we also do not want to cover up truth even at an early age.
She was born prematurely because the Nazis invaded her town and she was raised under the clouds of war, seeing from infancy the brutality and ugliness and body parts war brings. Yet, when the good guys, us Americans, came to drive out the enemy, she recognized that truth even at a tender age, instinctively ran out to greet the liberators. But they could not put blinders on the kids as they drove out the enemy. The kids saw what they saw and amazingly understood. Kids can be resilient in recognizing truth and not be traumatized.
I know several from that cohort and to a person, they are solid in their lack of traumatic damage. What good would shielding have done to any of them? None.
Well more than sixty years later, my wife retains a strong stable character in spite of or perhaps because of that exposure to horror. She has carried those same posters and she approves of the trucks. We have never thought of hiding kids from truth, would rather stomp out the killers. And that is what we are about.
I'm glad my parents were kind and caring enough to do so for me. I would hope that other parents would do the same.