The book is becoming apparent now even though the coverage is just the under painting.
This is a square painting but I have still tried to make the composition stable with a suggested triangle using the book as the base and the face as the rest of the triangle.
There will be a band of sunlight across the composition from right to left lighting the top of the book and the lower part of the face.
Having the top of the face in shadow will add dimension to the portrait. I haven't decided, yet, how dark the shadow will be.
When I am beginning a painting that I find challenging, I take a long time looking at it, and thinking about it between sessions and, if I am truthful, I am always a bit anxious about it being a successful work.