Final answer:
Introducing a foreshadowing element and not using it can lead to reader disappointment or act as a deliberate subversion of expectations, impacting the story's coherence and audience engagement. Chekhov's gun is a literary rule that emphasizes the necessity for every story element to serve a purpose in the narrative.
Step-by-step explanation:
Anton Chekhov's rule of writing, often referred to as 'Chekhov's gun,' implies that every element introduced in a story should have a purpose and be utilized later on, contributing to the story's coherence and sense of inevitability. When a writer includes an element of foreshadowing but fails to use it, it can lead to reader disappointment or frustration due to the unfulfilled anticipation or expectation. This literary device is a form of promise to the reader, and not fulfilling it can be seen as a broken promise or a missed opportunity in storytelling. However, an element that appears to be foreshadowing and isn't used can also be a deliberate technique used by the author to subvert expectations or to introduce red herrings in a narrative, although this must be done skillfully to avoid the perception of poor writing or an incomplete narrative.
Moreover, in accordance with Mikhail Chekhov's ideas about acting and imagination, the principle can be extended to suggest that the 'pistols' of the narrative—those crucial imaginative elements—should be vivid, expressive, and ultimately essential to the portrayal and understanding of a character's journey. A foreshadowed element that is never revisited can interrupt the audience's trust in the narrative, causing them to question the relevance of the story's elements and potentially diminishing their engagement with the creative work.