I can't explain it....but if you notice they are all looking at a different camera...maybe they were not ready to smile....I wouldn't put too much thought into this photo, the troops love him.........btw...I was just IM'ing with Jon while he was opening his Christmas presents I sent him.....(he couldn't wait, lol)...it was almost like being there, almost.
Thanks for your input.
I am so happy for you and your son that you can be in real-time communication while he's over there.