The Human Figure:

Like the pianist that always goes back to practicing the scales, painting the figure is, for the artist who attempts to paint people, at the core of artistic fundamentals.  The human body is mysterious and can be aesthetically pleasing.  Also, it affords the artist who paints or draws on a large scale the opportunity to "move a lot of medium around," in an attempt to capture the light and naturalness of a gesture and the subtleness of expression.