This is a striking image which immediately engages the viewer with excitement, action, a sense of fantasy and, if one is a horse person, affection for the central character. The colour palette is perfect, as is the mid-stride action pose of the horse. Zoomed in close, the blending of the horse with the background is almost perfect, while the choice to add the dust at rear and front hoof works very well to convince the viewer that this was simply a great photograph, rather than a photo-manipulation.
The light of the setting sun warms the whole atmosphere of the image, while the motion of the horse and the birds rising in the background point to some stimulus which has set both in motion.
(If I were to quibble, the angle of light on the horse does not quite match the direction of the sun - but one only notices this when one is studying the image carefully. It's a quibble, not a significant flaw.)
The horse is full of joy in his being, his strength, flexibility, power, speed and pride. The halter and braided mane point to his being much loved, while the absence of any lead or rein emphasizes his liberty.
The joy and life of the horse are emphasized by the stark setting, making the image more powerful.
This is an image which is inspiring and uplifting for all - most, I guess! - who will identify with this beautiful animal.