1. The drawing is okay for a first time - nothing special. Proportions seem alright, shading is meh.
2. What did I notice in drawing? Details! I would otherwise 'see' the whole without necessarily noticing all the minutiae that actually make up the image.
3. I'm an archaeologist and we typically draw our artifacts and features, along with photographing them. Why? Because photographs provide us with an objective, 'scientific' image (more or less), while drawings pull the subjective human mind into the object. In drawing, we represent only those details that help us tell the story's picture - the characteristics that are most important to us.