It’s bound to happen to a sketch artist; you get on your train and it’s empty. Or it’s packed. Or there may be a few people and they’re moving around. Or all you see are arms and hands and feet and legs. So what do you do if you’re sitting there with a sketchbook, a blank page, and a fountain pen? You draw the empty train, or the packed train, or the fidgety people, or the arms and hands and legs and feet. Either way, whatever you end up with is better than getting off the train with the same blank page you got onto the train with in the first place.