The X axis is time, the Y axis is steps or ingredients or something. The leftmost column is just ingredients. Check out the marshmallow one, for instance. The first step (upper left corner) is to soak the attached ingredients (gelatin and water) for ten minutes. The box below about boiling is simultaneous, but attached to different ingredients. The step after that is to mix the two batches you just produced together. Then mix in the salt until fluffy, then mix in vanilla. Let it cool for three hours, then cut it, then top with the final ingredient, which is powdered sugar.