ON ACTING: About Short Scenes and Good Acting
Emotional difficulty in a scene is forced on their character by the tenacity of the other character(s) in a scene.
The paradigm of a well acted long scene: character(s) enter the scene wanting quick, easy success, and are unexpectedly thwarted in their desires. The writer has created conflict for the characters--a conflict that the characters are committed to winning--and because of the writer's conflictual narrative construct, the characters are forced to ante up a long series of dialogue exchanges, sometimes lasting five to six pages, forced to come up with the emotional energy that underscores their verbal outpouring.
However, and this is the key point necessary for the actor to achieve good acting: throughout the scene, he or she expects every line of dialogue to be his or her last line in the scene; expecting their most recent logical outpouring of dialogue to the other character(s) in the scene to be correct and convincing, worthy of causing the other character(s)' capitulation immediately in the conflict.
Like tennis players who don't want long matches, neither do good actors. In a great tennis match, the ball always surprisingly comes back over the net...forcing another volley return...and another. Like good tennis players, good actors while preparing for a long scene, entering scene with deep emotional and physical reservoirs, try to win (and expect to win) each and every point as easily and quickly as possible.
Enter the scene expecting a short scene to occur; and let the scene--and the tenacity and skill of the opponent--dictate the subsequent length.