The professor talks about the comparison between the orchestral and two piano versions in relation to intensity and timbre: tension-relaxation, direction, climax and tempo. Reference to Horowitz's performances.
Other explanations to take into account are phrasing (feeling each phrase), pulse, dynamics, tempo accuracy, use of pedals (damper pedal), articulation, glissando (phrasing and dynamics), accents, sound quality, and timbre. The character must be gentler and not so eccentric. The phrasing has to be well built and the harmony, heartfelt. Finally, the student should work on an expressive sound and the end should be more conclusive.