This "warm-up" video first goes over what it calls as "bookkeeping" (from 21-to-35).
They establish that the "warm-up" will take place in c-major and will follow the chord progression: 2-5-1
So first she begins by playing the D-minor, G-major, then C-major.
Then she says that she's "minding the voice leading", and switches to playing a set of new chords that are not actually inversions of the previously played chords. (I had to look up what chords she plays) It appears as though she's playing: F Major, "G 7 no 5", and then C-major.
It sounds quite nice and similar to the previous progression, but I have no idea how someone comes up with that, or how this is still a "2-5-1" progression.
Any intution or understanding here would be greatly appreciated!