Chopin: mixer because he reminds me of one sometimes. Example.
Scriabin: He has written a lot of pieces for the left hand alone and he injured the right hand.
Rachmaninoff: He had really big hands. Really big.
Liszt: he sometimes reaches notes at the other side of the piano.
Ravel: he has delicate, water hands and very often the left and right hand play on top of each other.
Beethoven: he is powerful and this is also a reference to the hammerklavier
Satie: his touch is very gentle and it sounds like he is playing with gloves.
Boulez: Just to give you an idea.
Cage: the 'no hands' is a joke for 4'33'' and the objects on the keyboard are a reference to his prepared pianos.
Feldman: most of his compositions use just a few notes.
Mozart: Rolling pins because of all the scales.
Schubert: A lot of his pieces have very articulated right hand passages that go back and forth like a wheel and really easy left hand ones.
Bach: robot hands because he was so structured and calculating in his pieces. (Side note: amazing book)
Debussy: really soft touch, just like feathers.
Glass: Pendulum and metronome because of his style that led him to be very technical, a bit like Bach, but it's more complicated than that.
Bartok: drum beaters because of the power of some of his compositions.