What does Mary learn when she first sees red?

Frank Jackson imagined Mary in 1982, a scientist who knows every physical fact about color vision and has spent her whole life in a black-and-white room. When she walks out and sees a ripe tomato, she seems to learn something new, and Jackson concluded that experience must go beyond physical fact. In OPH an experience is an observer reading its own state, and reading such a state is the whole of having it. Learning about an episode is a different thing from undergoing it. Mary's books gave her the first, and the room kept her from the second, because her brain had never been in the state her books described. When she sees red, her brain is in that state for the first time. Nothing physical was missing from her books. What is new is an episode of red in her own history.