A face turned sideways can make a familiar conversation harder to read. One eye may disappear, the mouth may be partly obscured, and posture can become more noticeable than a full facial expression.
Find a scene in which a listener remains in profile while someone else speaks. Watch once for the spoken information, then again for the visible responses. Describe only movements you can actually see: a change in chin position, a held breath, or a turn toward the speaker.
Do not fill the hidden side of the face with an emotion simply because the dialogue suggests one. The restricted view may be part of the scene’s uncertainty.
Notice whether the film eventually gives you a frontal view. If it does, what happens just before that change? The new angle might clarify a response, but it might also make the earlier interpretation less certain.
Try a two-column note headed “visible action” and “my reading.” Keeping the columns separate makes a discussion more productive when another viewer sees reserve where you see discomfort.
The point is not to build a dictionary of gestures. It is to understand how the camera’s chosen access to a performance affects the evidence available for your reading of one particular exchange.
Editorial illustration from this site’s image library; not documentary evidence of the example or object discussed.