One is successful financially, the other is not. David Hettinger gives his opinion as to why.
"The differences between Bob and Don, besides their skill levels, is Don puts more of himself into each work of art and it shows. Bob produces a picture that one can find on any calendar. Bob doesn't put himself into his art, he relies on finding the perfect place to paint and capturing every detail of the scene before - that being most important. Don looks at the ordinary and puts his spin to what is there before him, making both his paintings and himself interesting. I'd like Don to refine his skills a little, that's just me being who I am, but I would not want to change anything as to how Don sees the world."