There are a few important points to consider.
First, all photography is selective. This fact alone creates a message. For instance, if a photography zooms in on a mob in action, then he or she is probably trying to capture the intensity of the people. However, there is no way to tell if the mob consists of a hundred people or ten thousand people.
Second, all photography is also from the biased vision of the person taking the picture. This is probably the most important point to keep in mind. For instance, if a photographer wanted to underscore the glory of war, he or she could capture courage. Or if the person wanted to underline the evils of war, he or she could capture the various injustices that are bound to take place.
In light of this, most Vietnam photos are negative in connotation, as it was a very unpopular war. Pictures usually depict innocent people getting killed. One of the most famous pictures is of a little girl running naked after a napalm attack.
When people say that a picture is worth a thousand words, it is true.