What exactly is different about this view?

Your gallery is beautifully trimmed in the Presentation View. The range of functions is reduced to the most necessary to avoid distraction from the most important things, your images. What remains is a pure, beautiful view gallery without annoying sidebar, with impressive, large cover photo, larger preview images, horizontal navigation, large gallery title, bright image view and so on. Only the download function is left if you have enabled it in the Gallery Settings.