ANSWER: Your brand statement tells your audience what your business and products can offer, that is different from what other offers. It shows how you're able to be better than your competitors in doing that business.
Because you were able to distinguish your self from others, with your brand statement, it shows how competency you're in leadership. Which has helped to develop your leadership skill.
Your brand statement can also improve your leadership skills, by giving you the opportunity to see areas you have to improve, to be able to beat your competitors.