What is the authors purpose for repeating the phrase "what next?" throughout the article?

Edison Marvels at the Magic of Electricity, was the article from one of the New York publishing paper where Edison was interviewed. Who doesn't know such great personality?! Thomas Edison, was an American inventor of some of the most amazing and useful electronic things. So what happened was, when Edison invented Phonograph, the people of the world questioned him, what next? And this question was being repeated by the author throughout the article. 'What next' is an expression used by the author to express the excitement and surprise. When they say what next? It means what will be the next innovation? What will be the next idea? What's next is simply a way of knowing what next!