This painting captures with perfection what starting to “see like a painter” looks like. When I started to paint more and more, I realised quickly that my vision, or the interpretation I made of it, changed drastically. Suddenly, I noticed that clouds had shadows and that the setting sun would colour the mountain, although, physically, the mountain was in front of the sun.
I became aware of several optical illusions in practice. For example, did you ever hear of the checker shadow illusion, where a chessboard shows grey and white squares, with and without shade on them? A white square in shade would have the exact same colour as a well-lit grey square, but our brain would always see the white square as being brighter.
As a painter, the difficulty is to make a conscious effort of finding and using the colour that clicks with its surroundings, creating a harmonious atmosphere.