Great leaders create companies that are fun to work for. Old school thinking is about power and and self-serving behavior. Agile leadership is about an open environment with no offices, flat organizations, continuous learning and improvement, information sharing and aware of your mission for making a difference in the world.
What is culture? A set of shared beliefs, values and practices. Check out Hubspot's culture at http://slideshare.net/HubSpot/the-hubspot-culture-code-creating-a-company-we-love
Look at a company's culture. It says much about that company's leadership.