Writers may enrich a story by using subtext to create more story depth.
Subtext is the hint or subtle undercurrent a writer inserts below the surface of his story. It’s what remains hidden and or implied from the obvious story details, but it simmers just enough to catch the reader’s attention. As the story unfolds, it is the story matter that is woven into the plot by use if imagery and words that show the character’s behavior to the reader. It’s importance becomes apparent to the reader as the story unfolds. It is implied or hidden information that remains loyal to the theme of the story.
For example: a love story about a boy’s attraction to a girl, but it’s hidden by his negative behavior towards her; a drug addicted character in denial with behaviors that show no one can count on him; Dracula, a vampire story with behaviors that show sexual desires.
Subtext is about hinting, weaving, application of imagery and symbolism into one’s plot without actually revealing anything. The writer shows, but does not tell. The reader forms his own conclusion about the hidden meaning beneath the obvious.