In Roald Dahl’s short story ‘The Landlady’, the landlady refers to Billy as Mr. Perkins because she is under the impression that he is a guest named Mr. Perkins, whom she has mistaken him for. This confusion stems from her obsession with having perfect guests in her bed and breakfast.
The landlady mentions Mr. Perkins as someone she has had previous dealings with, and this adds to the eerie atmosphere of the story. It suggests that she might have more sinister intentions, as she has perhaps done something to Mr. Perkins. This small detail enhances the unsettling nature of the story and illustrates the landlady’s somewhat deranged mindset.
Furthermore, calling Billy Mr. Perkins reflects her delusions about her establishment and her guests, indicating that she sees them not as individuals but rather as mere objects of her interests. This shows her inability to connect with people on a meaningful level, which plays into the themes of isolation and danger present in the narrative.