Thich Nhat Hanh described how one could draw in peaceful vibes and breathe out peace with a smile. It's been years since I read Miracle of Mindfulness, so I forget the details. The general idea is how a smile and awareness of breathing could flip a person into a state of mindfulness and relax body and soul. The other discussion of smiling occurred in 1975, the summer I worked in northern Manitoba on a track repair crew. I took a photo of a Saulteaux man and he didn't smile. He said it's foolish to smile into the camera, but didn't elaborate. The way he said it made the meaning clear.
Both views rounded out my understanding of the word smile. The smile could easily be used as a superficial, ingratiating or aggressive manner of steering a situation in a self-serving direction. The smile could also be frivolous. It could be an expression of ignorance or indifference about the state of the world.
Smiling is a huge topic, which I'm not interested in discussing, other than in the context of the dream lamp in the picture above and some thoughts that went through my mind while making the picture. The Mona Lisa's famous smile is part of the picture, as well as the smile of the Buddha.