One theme that could be taken from this story is that appearance are not an accurate reflection of reality (Lamb to the slaughter)

The theme was vital in showing that appearance is not an accurate reflection of reality.

The theme in a story simply means the main idea that's contained in the story. The theme is vital in conveying the idea of the author.

From the information given, the woman wasn't loyal to her husband as she killed him out of the shock at being divorced. She also tried to cover up her deadly act. Therefore, even though the woman was portrayed as a good person, she isn't really the kind of person she is.

Read related link on:

link

The three examples are that she is not loyal to her husband for she managed to kill him out of sheer anger/ shock at being divorced. Second is, she tried to cover up her crime and acted in a planned manner so that she will be taken as the wife of the victim and not as a suspect. Lastly, she tried and successfully covered up her crime, even to the extent of making the policemen eat the evidence, which will immediately remove all traces of her involvement in the crime.

Explanation:

Roald Dahl's short story "Lamb to the Slaughter," tells the story of how a woman killed her husband and successfully managed to get rid of the evidence. And one of the main themes that the story deals with is the issue of how we tend to overlook a person's true nature and be guided by preconceived notions.

Three examples of how the appearance of Mrs. Maloney is not an accurate reflection of her personality can be seen in her acts. First, the narrator presents her as someone who's faithful and loyal to her husband. But at the same time, she doesn't hesitate to hit him with the leg of lamb and kill him. Moreover, she also got rid of the murder weapon and didn't try to come clean. Rather, she went ahead to try to deceive the detectives and even act innocent. The narrator proclaims that "As the wife of a detective, she knew quite well what the penalty would be. That was fine. It made no difference to her. It would be a relief."

The second is when she went to the shop to buy things as a cover-up for her timeline. She planned everything, "tidied her hair, touched up her lops and face" and then went to the grocery store, talking "brightly, smiling at the man behind the counter", and acting as if nothing's wrong while the dead body of her husband lies in the house.

The third is her plan to perfectly execute the whole "surprise reaction" process in discovering the crime.

"she told herself as she hurried back, all she was doing now, she was returning home to her husband and he was waiting for his supper[. . .] when she entered the house, she happened to find anything unusual, or tragic, or terrible, then naturally it would be a shock and she’d become frantic with grief and horror."

This passage shows how much planning she did and also how she tried to justify her actions and be not convicted or discovered.

sorry but can you explain the question because i didn’t understand it