The form
One bar carries two chords. The transcription writes both chords' notes together without saying which note belongs to which, so that bar is printed and not drawn — a keyboard guessed from an ambiguous line would show a chord nobody plays.
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.
C7
bar 9
LH C3 G3RH E4 Bb4 D5
B7
bar 10
LH B2 F#3RH D#4 A4 C#5
Bb7
bar 11
LH Bb2 F3RH D4 Ab4 C5