Ideally, she would have said something along the lines of "Oh, I love bellybuttons! They are little works of art. And like fingerprints or snowflakes, no two are the same. I love it when people compliment mine, which is why I show it off so much."
Let's be real, not everyone thinks as highly of bellybuttons as we do. My guess is that Briana's more proud of showing the hard work of all her exercising when it comes to all her belly baring, and her bellybutton just so happens to be along for the ride, so to speak. Still, I love the fact that she answered the question.