Seems as if they know you're taking a pic and the horse in front is the prankster... The background reminds me of painted scenery in 30-50's Westerns...
I'm not sure why I am so taken with this - I could point to this and that and the other, but I suspect the magic is in the way it all hangs together naturally and improbably.
Nice looking horses, like the way their heads are lined up. [I suspect you had to sacrifice the tone on the clouds in order to get the horses looking OK given the direction the light was coming in.]