This is a composition with the express purpose of learning to draw a particular kind of subject. It starts with the understandable premise that you don't already know how to draw this thing as it exists in the world or in your mind.
So you EXPLORE how to draw it by trying different ways to draw it out.
Each time you explore another way to draw it you get closer to understanding how to to it.
You also get familiar with how you want to do it. And you might also discover that you may need the actual object, better lighting, some photography to assist you or even some additional instruction and practice.
Doing studies are necessary for all artists -- no matter their level of drawing ability. Artists who work all the time know this and they think with a pencil in hand.