Photographing people in their natural states, unposed and off-guard, presents different challenges. Truly photogenic people are rare. It has little to do with attractiveness or having a fabulous smile. It has more to do with the natural and consistent state of their faces.
I’ve taken many posed photos of friends and family members and, for the most part, they all have the same exact smile in every photo. It’s a well-rehearsed smile reserved for photographs and greeting people.