This is how fluidly the person changes emotional state and how willingly she expresses it. Expressive Expresses emotions naturally. Uses different emotions appropriate to different circumstances. Responds to situations by feeling something and expressing it. Emotional state will be quite apparent to others.
Emotions are a fluid response to life.
Suppresses responses to circumstances. It is unclear to others what she feels about the situation. A Closed Off person would be uncomfortable by being pushed into emotions. She would probably rather want to talk about things and would need to be inched gradually towards feeling more. An Expressive person probably doesn't want to waste time on that.