Those clouds where the spreads occur are not at different altitudes relative to each other though each is at a different height from the bottom of the picture. It's a matter of perspective due to distance, just as in the second picture those dark clouds are at a lower altitude than the brightly lit ones below it though they are higher up on the photo because 1. they are not typical high altitude clouds like those in the distance and 2. they are much closer to the observer (as evidenced by the fact that they are, as is the observer, already in the earth's shadow, as the other clouds at a farther distance and greater height are not).
