Wednesday evening began with a lecture on Value. Value refers to the gradations between light and dark. Values are influenced by the lighting conditions and the planar structure of an object. For instance, rectangular objects have hard-edged value transitions; whereas curvilinear objects have smooth, gradual value transitions.
Justin Edwards' drawing has similar areas. Although the drawing is very well composed and the values have been accurately reduced, the white areas in the bottom right corner shouldn't have a line around it. The same is true for the skull and the pale behind it. One solution, would be to have a broken or open line instead of a completely enclosed shape. All in all, still a very good drawing.