It takes a visually literate viewer to appreciate such a fine image as this -- as Tim so beautifully notes, the burst of light at the mouth of the horse is the catalyst to the imagination here. Is it breathing fire? Screaming defiance? Or the horse from hell? You leave the answers to us.
Sometimes it may seem to the casual viewer of images that they are just quick shots taken on the fly - but this image is an example of the art of photography. You have taken time to frame this image and to place the bright light at the mouth of the horse. This is a quick shot - this is the art of photography.
