When he finally barks out his affection, Karen seems stunned and drops a large piece of cake, hardly a romantic gesture. After the mutual admissions of love, the film begins to focus on that relationship. Not only has the lesbianism been erased, but the entire question of power relationships vanishes with it. Through similar conventions, Martha tells the audience that she also loves Joe. The first clue comes in the scene where she takes off her glasses before Joe can see her with them on.
Every moviegoer knows how to read that gesture.
She wants Joe to find her attractive. In movie parlance, glasses disfigure a woman's face as much as they disguise Clark Kent's. This early scene establishes how much Martha wants Joe to like her, while the later declaration scene lets audiences know that Martha has been replaced by Joe. The coupling of Joe and Karen, Martha's reaction, the anticipation of a rupture and its resolution become the plot of the film. While the play locates the source of the rupture in the power which Mrs. Tilford can wield and in society's determination to enforce a sexual norm, the film evades entirely the issues that propelled the original drama.