In the Tell Tale Heart the biggest imagery that was used was the old mans eye. It made the entire story because the narrator hated his eye and it made him insane so he decided to kill the old man because of it. It was very large and had a blue film over it.
In The Tell Tale Heart the Narrator would hear things that weren't there like the heartbeat of the old man after he was dead. This made him get caught by the cops because he couldn't handle the pressure.
Every night the narrator would go to the old mans house for 7 days without doing anything. He did this because if it was the eye that he had a problem with he would need to see it if he wanted to kill him. When he did see the eye on the eighth night he tried to do it.