We don't smile or look directly at the camera as much, because we feel like sometimes it can ruin a good image. More like a nice picture than a nice stock photograph. Neither of us really struggle with confidence issues though the youngest is only 15... I don't think any teenager is a 100% comfortable.
I'm not so sure it stops with being a teenager do you? I for one at least and a giant portion of adults are not so comfortable in our bodies either. I've always thought I'm not so good looking or my stomach is a bit to large even though I'm 6'1'' and 190 pounds and an athlete. I never think a girl will like me and that I have to work extra hard to get adults to like me. I think my art iss always poor compared to everyone else and even though I spend my life studying...still I'm not so sure I really get anything about life.
The only time I ever feel really good about myself is with any animal or any children. Those groups seem to always...always love me instantly and for that gift I'm forever grateful.
I think the looking at the camera at times at least makes it so much more personal...as if you took the shot just "FOR" that one person. Anyhow..that's just my thoughts.