One of the jobs of a painter is to only paint what moves them and not to paint what looks it'll sell. It's vital that something in the imge moves the painter to want to capture it. If the artist feels an excitement about the subject, it will show up in the painting. This all sounds really obvious but it's amusing how often people are surprised by it. Friends are always suggesting subject matter to me; musicians at a festival, a particular valley view, etc. What they're saying is that that image moves them and they wish it moved me so I'd paint it! Commissions are another story. Hopefully the artist is painting commissions in a certain field, pets perhaps, that they specialize in so they can get exctied about painting another dog. It's no news that we do what we like to do though. I wanted to paint Poolside Dining because I loved the pattern of the umbrellas and their shadows. Giving a reasonable explanation for what moves me is not part of this blog!