One cannot explain paintings or the act of painting. Any law, rule or scheme is a contrivance that turn art into a recipe. In this detail I am faced with the back of a man that needed recolouring with no reference material or memory to work from, and no clear idea how I was to do it, only, I sort of knew that realism was not it. I can only trust my hands to deliver pigment to the canvas while I watch - on occasions I call for a revision or perhaps a rerun as I am unable to specify what I want done, this activity continues with various areas that seem unsatisfactory. I have worked all day like this with both minor and major alterations - now, we are both more or less happy I can clean up and have some supper.