The Pentateuch as a Painting

In John Sailhamer's The Meaning of the Pentateuch, he compares interpreting the Pentateuch to interpreting a Rembrandt painting (p. 150). Here is his paragraph.

Since the biblical narratives are like an artist’s painting, in order to understand a painting, we must look at what the artist has painted on the canvas. We would not attempt to understand a Rembrandt painting by taking a photograph of his model and using it to fill in places in the painting that are not clear or are cast in the shadows. That may help us see or understand the people and places Rembrandt painted, that is, his subject matter, but it would not help us understand the painting itself. To understand a Rembrandt painting, one must look at it and see its colors, shapes and textures. One must understand what he meant to do with each brushstroke. In the same way, to understand the Pentateuch, one must look at it and the words of its author.”