A moment of happiness that can only be felt if you were there to experience it first hand. Louise's dog is just happy to be there, and exhibits that by yanking that towel while she runs away in pure bliss by the beach.
It seems rare to display this kind of happiness, but it was the first time in awhile that she has felt this free on her own. Nothing can stop her. The smell of the ocean breeze is enough to keep her happy in this one moment, and that is all she will ever need.