Highsmith's Use of Forshadowing

While reading this novel for the second time, I am picking up on events that foreshadow other key aspects that come later in the novel. One of these was the fact that Tom is already playing “a role” on the ship. “He began to play a role on the ship, that of a serious young man with a serious job ahead of him.” Based on this statement we see that Tom enjoys acting as others. He is not satisfied with himself; therefore he takes on different personas. From already reading the novel, we know that Tom not only creates a new self but furthermore impersonates Dickie.
On the ship, Tom admires himself in the mirror one more time. When he first looks at himself he sees a “conformist face” but when he places on the conservative English wool cap he sees a “young man with a private income.”Once again, the mirror is symbolic for how Tom views himself and how he will later see someone else staring back at him.
Does this foreshadowing make the story more interesting or does it rather give the reader more insight on the thought process of Tom Ripley?