That's just good use of a telephoto lens to convey the true perspective of the hill. If you use a normal lens from close everything recedes into the distance; it's the same effect that you see in car wing mirrors, which are slightly convex so as to take in as much view as possible.
If you position yourself a long way away from a subject then view it through binoculars or a telephoto lens you eliminate the effect of perspective and see everything in its true proportions relative to its surroundings; the effect can be quite startling and very revealing.