In America, if you are not smiling, some people will actually tell you "SMILE!"
It annoys me, but that's just the culture here. I don't always understand it really.
As for that photo, I was specifically told not to smile when they took it. It was the procedure of the time for all official Soviet photos.
Interestingly, in the US, some states are starting to ask people not to smile when they take drivers' license photos, etc.