I think it is a noun phrase, and not appositive.
Answer:
adjective
Explanation:
it resembles without being identical
The cask of amontillado is about a man named montresor who wanted revenge on a man named fortunato cause of an insult that was made. They meet at a carnival and montresor lured him into his home to bury him alive.
The irony is that they are smiling with “torn and bleeding hearts”.
The idea it emphasizes is that they are smiling to hide their pain.
The overall message revealed by the irony is that they are in considerable emotional turmoil and faking happiness to mask their distress.
