Most Helpful Guy
Well, considering I'm the exact opposite, I can tell you that is most likely has to do with the structure of your face and the sharpness of your features. For me, I can't take a good picture because my cheeks are kind of round (especially now since I'm chubby) and my features are not sharp or defined (time to do more cardio...). This results in poor depth perception so the details you see in person are not captured because of the average camera's limited exposure.
With a symmetrical bone structure and defined angles, your strong features pop out and that creates depth perception. I could be dead wrong as I am not an expert in this field, however I simply used my ugly duckling photo genes as a point of reference.