The changes
The hands
Left hand then right, as the source writes them. A pianist's voicing routinely carries a colour the chord symbol does not spell — a flat ninth over a dominant, a ninth on top of a seventh chord — so the notes printed under each keyboard are what is actually played, rather than what the symbol alone would predict.
Cm7
chord 1
LH C3 G3RH Eb4 Bb4 D5
Abmaj7
chord 2
LH Ab2 Eb3RH C4 G4 Bb4
Dm7b5
chord 3
LH D3 Ab3RH F4 C5 Eb5
G7alt
chord 4
LH G2 Db3RH B3 F4 Ab4