What a fun challenge! I noticed that I often spend too much time on a painting and make it look "tired" or overworked at the end. So this exercise was perfect for me. I set my timer for 15 minutes and worked on the first square, stopped when the timer went off, changed the light, set the timer again and repeated for all the squares. I never had time for the details, but that is ok. It didn't really matter. I liked that there was no time to overthink.