Depth and shadow

BIC - Matic Grip Mechanical Pencil, HB #2, 0.7 Reeves 451474 Reeves Oil Paint (Google

Yesterday, Krystal said this painting looked pretty much like someone threw up yellow all over a canvas.  It lacked depth.  So, I'm trying to remedy that with shadows.  It's a small painting, so a little hard to do much in a teeny weeny space.