German PoWs in American captivity forced to watch footage of concentration camps. Taken soon after the end of World War 2, location unknown.
The majority of the German POWs sent to the US were captured later in the war and did not join in the German army by choice but rather by force. They were not supportive of Hitler’s agenda and only fought in fear of what the Nazis would do to their families in retaliation. So in this case, it is likely that they were genuinely appalled by what they were seeing or did not want their picture taken.