This exercise is an example of how cable work has some advantages over a barbell in that the loading curve matches the strength curve, so there's constant tension on the delts from start to finish.
The other advantage is that most of the initiation of the movement comes at the shoulder joint rather than the elbow joint. The synergy between these two components makes this movement an awesome shoulder developer.
There are times when the world is against you, when you girlfriend left you, your momma don't love you, and even your dog don't much care for you. That's when it's time for the mental therapy that only a brutal training session can provide.