this is superb playing--he's hearing the music then letting his fingers, wrists,arms, body, cause the piano to make the music.
The fingers lift, just the right amount. The playing is not ostentatious, but just right--however, I bet Mozart took every opportunity he could to show off!
this is good music. I want to talk more about the musicianship than the playing of the fingers/body, which seems to me about perfect.
In looking closely though, to me, it looks like his palms are closer to the keyboard, which lets the fingers fully extend, even while keeping the arch. I see many pianists who seem to "over curve" the fingers and the playing is done with almost all fingers.
Here, his arch is flatter, just above where some of the fingers might collapse, and not so high that the fingers are playing and leaving the rest of the body, behind. In other words, his hands are in the perfect spot to let his fingers go high or low as needed, very active, and put the whole body into it, all while keep that low arch, perfectly there: which makes this Mozart sound so easy, when it is really, very difficult.