How does Noel Coward use imagery in Private Lives?

In the tightly-scripted first Act, Coward achieves another kind of balance, through the individual scenes of the two newly wed couples, which lead up to Elyot and Amanda's reunion In alternating appearances, the couples are presented as mirror-images of one another, separately enacting the same scenarios with an exaggerated symmetry, down to the pacing and content of their dialogue.