Before and After

Mondoweiss posted this photograph as a "before and after" evidence. 

I don't get it. The "before" photo shows a valley between two mountain slopes. There is a group of trees in the middle but the mountain slopes are bare, brown and rocky. The "after" photo shows a valley between two mountain slopes. The valley in the middle is bare and seems to be covered by some sort of sand. The mountain slopes on either side of it are green and covered with trees and grass for as far as the eye can see.

So I really don't understand what kind of a before and after this is. How long has elapsed between the before and the after? How long would it take for the trees in the after to grow on those bare slopes of the before? How many years, or seasons, hours, would it take for those slopes to turn green? And how come neither the author of the piece nor any of the commenters noticed this anomaly? Perhaps someone can enlighten me?