RULE OF THIRDS - The rule of thirds can be seen at the left side where the first fence post is sitting in the frame. On the right side we also see the the rule where the fence stops and the empty space starts.DIAGONAL RULE - This rule is best shown with way the fence tapers off. You can also see many diagonals all through out the branches. These lines are much more subtle do to the color. The fence posts are much darker than anything else in the frame, making this diagonal the focal point. And again the beginning of the line starts on a third.
VECTORS - Is this image both graphic and index vectors are at work. The weaker of the two being the index. The tops of the fence post are arrow shaped and, to a degree, lead your eyes upward. However, the graphic vector is much stronger and pulls your eyes back into the picture. The diagonal of the fence start the motion then passes it off to the road and pulls you to back to the mountain in the distance.
