Was the piano a real instrument, or an electronic keyboard?
If it was a real instrument, most likely the vibrating strings inside it were arranged in a fairly complex pattern, with the low note strings running diagonally under the midrange strings. In other words, the acoustic, unamplified instrument does not arrange for low notes to be on the left
Was it a concert grand piano, or an upright? If a concert grand, was the soundboard (lid) closed, open or removed completely? Was there just one microphone for the piano, or two, or a whole array?
Most likely the sound engineers electronically panned the piano sound based on frequency. Incredible sound. Unbelievable sound. Indeed, but I for one prefer believable sound