Ten minutes before the start of Daniel Radcliffe’s one-man show on Broadway, Every Brilliant Thing, the actor is crouched in the aisle. He presses a card into the hand of a woman sitting six rows from the stage and instructs her to shout the line written on it when he cues her. He gently touches her arm to reassure her, and she flushes. As the former Harry Potter star walks away, another audience member—a stranger—leans across the aisle. “Are you OK?” she asks before brandishing her phone. “I