Dr. Carlson enters the Kwons' hospital room. She introduces herself but realizes they speak no English and quickly moves on to performing an ultrasound.
Once it begins, Sun immediately remembers the last time Juliet gave her an ultrasound. Juliet and Jin look at her, concerned, but when the child's image appears on the monitor, Jin begins recalling their lives as well.
They remember when Jin learned Sun spoke English and left her. They remember his boarding the raft after they reconciled. Their remember their reunion on the beach later, then they remember Sun sharing the news of her pregnancy. They remember Jin massaging her stomach in their tent one night. Then Sun remembers bringing Ji Yeon to his grave, and she begins to cry as she remembers Jin's death. They remember him running to the helicopter, and Sun's screams when the freighter exploded. Then they remember their reunion three years later. Finally, they remember holding each other as they died.
Sun cries after remembering it all, and both are silent for a few seconds. But then they look at each other and smile. Their emotions overwhelm Juliet. The two then speak to her - in English - and she leaves them.
An ultrasonic flash is a photographic enhancement. During the scene, Jin and Sun flash during an ultrasound.