Gasquet usually takes his racquet back quite high in preparing for his topspin backhand, even higher than for his slice backhand. His loop backswing is large for a backhand, but still small compared to many forehand loop backswings. Arguably, the advantages of a loop include developing more racquet speed early in the swing and helping to get the racquet well below the ball to produce topspin. The counterargument would assert that a loop isn't necessary to produce those effects, that a loop makes timing more difficult, and that a loop can make the player drop the racquet head too far below the hand at contact. In part because the backhand loop is relatively moderate, but also because the biomechanics of the backhand are quite different from the forehand, most of the debate about loops is focused on the forehand. On the backhand, you're unlikely to get yourself into much trouble by experimenting, and you're likely to find your own optimal amount of loop, if any.
Notice that Richard is looking over his shoulder to see the ball. That's a good way to make sure you've gotten your upper body turned properly on the backswing. Having the left hand on the racquet's throat also helps to turn the body, and it gives you better control of the racquet.
Gasquet is using a backhand grip close to the modified Eastern.