https://docs.google.com/presentation/d/1lwKLkk6sfl5GlOX9k0_8dDpc206KHDfndZumSQxL3VQ/edit?usp=sharing
The differences between the smiles and not smiles people can come off as not happy or rude but when they smile they look more comforting. A job of a photographer when asking to take photos of people is not to make them feel uncomfortable.