Along with the charisma and the extreme winsomeness, Rudd is uncommonly good at embodying what nonactors spend all their energy trying to conceal: every category of pain, from the glancing to the trenchant. This is a talent with sweeping applications. It is funny in broad comedies, biting in prickly indies, germane in anything romantic. It is charming in real life. You could argue that a 46-year-old actor choosing to play an antlike creature is a study in the entertainment possibilities of pain. What’s more emasculating, as a class of metamorphosis, than miniaturization?
‘‘Pain’’ is obviously too dire a word to describe Rudd’s 2 percent milk face-plant. But it was still a useful demonstration, especially when you think about how invisibly most people respond when they’re uncomfortable (by freezing up, gritting their teeth). Inventive expressiveness (of vulnerability, of suffering) is so rare. It’s what makes certain people enchantingly sympathetic and certain characters relatable.