The horse in this photo is running from right to left, but the text is English and so left to right. The visual impact of the horse racing one direction slows down the pace of the entire document because it is going a different direction than the text.
In Western cultures, because our languages move from left to right, we have come to associate a visual direction of left to right as being forward and fast, while right to left is more backward and slow. When you are creating a layout with a connotation of speed, you should remember this - and keep your images moving in the same direction as the text.
