The bokeh is pretty nervous (more than the 50/1.7 would make, for sure) but I think that, for this picture, it somehow gives a nice touch.
Technical consideration: slightly front focused maybe? The artist's hand and foreground shoulder are in focus, face is not. I would have cropped a bit from the left; the right hints at the subject of the painting because it's where the eyes are looking to, but what is behind the artist? It doesn't add a lot I feel.
In any case, it is a nice picture and I think it manages to capture the "feel" of the idea very well