I also upload a video on the 2nd piano part.
https://youtube/ELcW-Nl5uTU
I put a two- beat octave left first, which was not found in the sheet music.

Practice playing the 1st piano a lot. Turn on the 2nd piano video and start with two beats of the left cord.You'll get twice as much pleasure as you do alone.

Play the first piano with the accompaniment playing.That's what "Lisa" did. 

Um...It sounds a little bit different than two pianists played, but...It means to make something that you can enjoy alone.