It’s entirely summed up in her trip into No Man’s Land on the frontlines, and it’s why that particular sequence will be remembered for decades to come.
It’s a feeling that is completely absent in all of the DC Extended Universe movies that precede it, and puts it a head above them all.
It certainly helps that Gal Gadot sells the hell out of this attitude, but it’s also just downright inspiring to watch within the context of the story being told and the atmosphere of the world into which the film is being released.
Rather than being burned by power and responsibility, Diana is entirely free and literally living in paradise before the story of Wonder Woman really kicks off — and everything that happens in the movie happens because she feels that it is her duty to do everything within her abilities to help the world.