You did a amazing job with the light angle- it's just how you used to shade the light. I'm not trying to be rude or judge your art I'm just saying, if you do do shading next time with realism, try using a light color and not use the rolling tool thingy. I would suggest using the pen thingy and using lighter colors of that color, it'd look more realistic. If you don't understand I can attach a anim on what I mean