KaPOW! What striking, dramatic contrast and structure?! Not only is there clear evidence that your'e observing the edges/contours & details carefully and recording them accurately- but you seem to have a gift for perceiving light and shadow! If anything, you could work on a little more nuance/subtlety on the fingers themselves- but the shadows across the hand as a whole are so well done that it more than makes up for it. Our eyes really see this as having depth. Thank you for working so hard on this and taking it so seriously.
This is really cool.
Everyone is encouraged to re-read pp.46-48 in 'Drawing on the Right Side of the Brain' and repeat this exercise as often as you want to to build both your perceptual skills and your mental L-to-R mode shifting skills. Everyone is also welcome to re-submit this assignment (decorating, filling with zentangle, expressing & interpreting the positive & negative spaces of the vase/face illusion) for a higher grade before the end of the semester.