God, that would explain so much.
"Watching Whishaw in ‘Lilting’ is a little like watching Garbo in one of her lesser vehicles like ‘Romance’ (1930) or ‘Inspiration’ (1931). As with her, Margaret Sullavan, Gérard Philipe, River Phoenix and a few other very special and gallantly vulnerable players, just put the camera on Whishaw and that’s really all you need for a movie. He is one of the few working actors that you really should see in everything, and though ‘Lilting’ doesn’t give him enough to play with, it does offer the pleasure of watching him in the full flower of his dogged, little-brother-ish, quicksilver inspiration.” (rogerebert.com)
Aka, the Dietrich effect: you can’t look at anybody else on the screen…