These are the notes that are being played in the video. Try it and see. It should match up note for note. If there is a discrepancy, let me know and I'll fix it. It was pretty late last night when i did it and I have been known to make mistakes in the past! lol
It's the major scale in diatontic (within the scale) thirds -- alternating ascending and descending. I didn't analyze the entire exercise, but let's take a look at the first two bars . . .
Using the first four notes of the C Major scale: C D E F
1st Bar
C Major - (Ascending) C to E: A Major third interval (1, 3)
D minor - (Descending) F to D: A minor third interval (b3, 1 for D minor) or (4, 2 for scale degree)
2nd Bar
E minor - (Ascending) E to G: A minor third interval (1, b3 for E minor) or (3, 5 for scale degree)
F Major - (Descending) A to F: A Major third interval (3, 1 for F Major) or (6, 4 for scale degree)
The third bar starts with an ascending Major third interval - G to B. And on and on. That's about as far as I went with the analylization, but this should give you a pretty good idea of what is going on with the entire exercise. From there he just modulates the exercise in half step increments to cover all 12 keys. Oh, BTW, the last note on the bass clef should have been notated as a Db and not a C# (just in case your reading the bass clef). But I forgot to go back and change it before I posted.
Hope this helps!