At first I thought that the landlady had a memory problem and the boy was just being empathetic towards her and not question back to trouble her. But I guess she was portraying herself this way. After he started drinking the tea she became a lot better at conversing which was suspicious and I guess the game was set at that point. Also the author emphasized on the fetish of the old woman to stuff her pets which she loves dearly. The story is moving on the basis of how one perceives things at first and how everything first perceived by the boy was wrong about her