These are studies done in about 2 hours, one per week.
What do you do when the model isn’t giving you anything you want? You paint one of your fellow artists. (Preferably the one that stands more still than anyone else!)
That scratch on his nose shows you how you should sand or scrape your re-used canvases before you start using them again. It’s a build up of gesso or a brush hair imbedded in the gesso.