Summarize: "In her testimony, Mary Barra demonstrated leadership by acknowledging the company's mistakes and outlining a vision for the future. She accepted responsibility, which is a key trait of effective leaders. This helped to restore trust and showed that GM was committed to change. At the same time, she also demonstrated managerial communication by discussing the specific steps GM was taking to address the issues. This included making changes to their safety processes and procedures, and holding individuals accountable. This type of clear, directive communication is typical of a managerial style. So, while the context is different, the type of message Mary Barra sent to Congress can be seen as similar to a message a manager might send within an organization. Both leaders and managers need to communicate effectively to ensure their teams understand their goals and expectations, and Mary Barra's testimony was an example of this