This is the second horse painting I was talking about yesterday. It is large, 24" x 18", on gallery wrap canvas painted on all sides. The reference photo used was by kind permission of Ainslie Gilles.
This lighting effect is known by its French name of contre jour (literally, "against the day"). It is a seventeenth century painting technique that refers to the illumination of a subject from behind that appears in front of, or against, the light. It was (is) popular with French and American impressionist painters. It is challenging to pull off, because the deepest shadow on the subject is at the forefront of the picture, but I like it for the dramatic effect.
Now to decide which painting to enter into the competition, if any. It is such a lottery entering competitions.