great photo. I like the way it creates great curiosity about what is going on where the his camera is not pointing. Is it a general annoucing a great victory, or a movie actress giving a USO tour? And it show how smart the one fellow is who is wearing his helmet!
Allowing some open sky in the image is important to the comic aspect of the photo. One can imagine the need to squeeze in tight if it was indoors, but the addition of the sky makes the tightness of the group of photographers even more hilarious.
I supose "decisive moment" would apply to this photo. The range of activities, from putting in a new flash bulb, taking notes, movie camera, et al, makes the photo more interesting.