The branches of the tree lead the eye down to the parallel lines of the horizon. These in turn lead us to the elephant.

Example 2

The eye-line of the girl leads us directly to the ball, the eye also follows the implied line created by the arm up to the ball. Also note the implied triangles created by the position of the body and ball.

Image 3

The eye-line of the butcher leads us directory to the subject, the slaughtered bird. The eye can also follow the arm, or either of the strong verticals to be lead to this point.