Answer:
It illustrates the plato stage. When the love and affection are stabilized and the couple does not feel excitement or urgency for each other anymore.
Explanation:
First the couple was extremely passionate, with a natural addiction, because of the dopamine activation in the brain area. No wonder people says love is a drug.
However, the dopamine levels discrease after some time, and the couple can experience the plato stage, when passionate love fades and a more mature form committed of feeling takes place.
The couple tends to develop companionate love, which is a lot different from the lustful frenesi of the begining of the relationship.