The second step of the slice backhand is to take your tennis racket all the way back using your arms as well as a continued shoulder turn. In the video above, you can see me shadowing this motion. Once I’ve pivoted with my outside foot and turned my shoulders sideways, I then use both my arms and shoulders to get the racket all the way back. What you can see here is that getting your racket back on a slice backhand is different than getting it back for a topspin forehand or topspin backhand groundstroke. What you want to do is get the racket over your back shoulder and behind your head, and you want the racket and your forearm to form an L shape.
If we look at that from the front at 0:50 in the video, you can see that the racket is behind my head with the racket face open to the oncoming tennis ball, and my hitting arm and racket are in an L shape.
Let’s now watch Oliver get his tennis racket back. Having pivoted and turned his shoulders sideways, he now uses both his arms and shoulders to get the racket all the way back. He brings the racket around behind his head with the face open to the tennis ball, and you can clearly see at 1:10 in the video that his hitting arm and racket form an L shape. From the front view, you can see that the racket is behind his head and above his back shoulder.