Jack Laffan differs from his sister, Margaret, in several key ways. Firstly, Jack is described as a sociable man who enjoys spending time with his friends and engaging in conversations, highlighting his outgoing nature. In contrast, Margaret is portrayed as isolated and grim, having lived alone for twenty-five years and choosing to keep to herself, which suggests that she is introverted and possibly withdrawn from social interactions.
Additionally, Jack is under the influence of his domineering wife, Mrs. Jack, indicating that he has a certain level of dependence on her opinions and decisions. This contrasts with Margaret, who appears to be self-sufficient and independent, even if her independence leads to her isolation. Overall, Jack's sociability and connection to the community stand in stark contrast to Margaret's solitude and mystery.