Personality and character are two very different things. The interviewer is looking for more information on your traits vs. your integrity. This example could include buzzwords such as extroverted, energetic, and confident. For Southwest, it doesn't hurt to be more extroverted and energetic. But don't worry; it's not a deal breaker if you are not. As they state on their careers website, "No matter where you're flying from or what area of Southwest interests you, we're connecting each other to what matters most. We recognize that every experience, perspective, and background makes an incredible impact on our Company. We encourage bringing your authentic self to work and celebrating what makes you unique!"