This exercise aims to help in two key areas
The second of the lateral wrist movement exercise builds on the basic position shift that we learned previously and helps us to locate positions on the fretboard purely through proprioception, that is knowing where your hands are in space without having to look at them.
The first exercise developed a clean relaxed position shift, this one takes advantage of that to get you comfortably changing position up and down the neck. In addition you'll build some muscle memory that will help you find the note with your left hand simply by referencing it proprioceptively. That is you're motor and sensory systems will remember the distances between notes so that you are less reliant on looking down at the fretboard.
Play the D on the 7th fret third string with your first finger and then the C two semitones down on the same string with your second finger, moving from the 7th position to the 4th. There are a number of things to note here:
Do this exercise slowly at first and gradually increase it until you notice any tension in your hand, arm or shoulder. Slow down just enough so that you can stay relaxed and do the exercise there.

The left hand exercises aim to:
Play a simple progression, I'm playing a 12 bar in E in the 5th and 7th positions, and at the end of every bar or 2 bars reorient your left hand by taking it right away from the neck or at least from that position. Don't look at your guitar, start with chords you're comfortable with and then try more challenging ones, different tunes etc.
This exercise involves playing firstly an A major and then an A Lydian dominant scale in the 9th and 14th positions. Again we're working on smooth position shifts that start with gentle rotation of a neutral shoulder and progress to very slight lateral deviation, or rolling, of the wrist.