It is known by different names depending on the author, Bucket Cast or Hump Mend being the most popular ones. I first read about this technique close to twenty years ago now. At the time I was far from possesing the skills needed, as proved my clumsy first attempts. I used to comfort myself by thinking that its use in practical situations was very limited; but that was just a cheap excuse to avoid some frustrating training sessions.
It isn’t that unusual to find a fish feeding in the slack water upstream of a submerged rock, or in the pocket water behind it, is it? There, a conventional straight line cast leaves the fly line at the mercy of the fastest currents downstream of the fish that will make your fly to drag immediately.