How does Linh feel when he sees a picture of Helen and Darrow and why does he feel that way? What does he think about the picture?

One week after Linh had been introduced to Helen, he notices a picture of Helen on Darrow's table. Linh is surprised at the photograph. Linh feels betrayed and jealous because he did not know that Darrow had been on assignment with Helen. It was common to see American men with Vietnamese women but no one had ever seen Darrow with another woman.