And why wouldn’t He express joy upon healing a blind man? Jesus seems to be generally portrayed as emotionless or concerned/sad; at least that is my impression. The smile is a really nice touch. It was the first thing I noticed in that painting. I don’t think I have ever seen it before.
Well-argued. He is 100% divine and 100% human; God invented humor and is its Chief Practitioner, and humans smile and laugh often.