Gorgeous photo. I assume the lighting is the the sun lighting up the floor, while the horse emerges from a dark barn... then Photoshop MAY have been used to black out the background. When I make wallpapers and such, I frequently blot out the non-key parts of the picture (ie, fill them with flat colors, or blur them)... It makes the main part of the picture a lot more focused, and everything feels more clean, less busy. You can't do that to all pics, but sometimes it's the ticket...