This is a picture of Shank with his best friend in the whole world, Minnie Pearl (the little appaloosa). Shank loved Minnie so much that when he was out in the field with her, he couldn't eat for fear that some other horse would come around and "lure" Minnie away from him. He would stand guard over her which is exactly what he's doing in this picture. Minnie went to the Rainbow Bridge two years after Shank. I just know he couldn't rest until she was back under his watchful eye.
Rest in Peace, Minnie. We miss you.