The superimposed exercise is the first one I ever learned from Peter Han - probably before I even took his class, as he's shown it on a few youtube videos as well. It is however important to note that while some of my exercises are based on what I've learned in the past, I'm not always employing them the same way, or with the same focus.
Keep this in mind, in order to avoid any mixed signals. When doing the exercise for Drawabox, follow my instructions even when they stray from Peter's own. When following along with him, do what he says instead.