We can learn a lot about conflict and effective drama from this play. Each scene and beat are crammed with conflict. The choices of the characters and the decisions they make are very much like a chess game--each a calculated move in order to gain position and power. As you watch this film, consider how equal strength antagonists face off and create the intense drama of this play.
You may also pay attention to film techniques. Notice what the camera is doing, how it creates POV, for example. Notice how lighting and music help to create tone and mood. Notice how the effective portrayal of an actor can make a character on the page come alive.
Information about James Goldman and the film adaptation of The Lion in Winter can be found at the links here.