The first video gives a nod to the stereo speakers, though it is mostly about slow-mo video. It shows how easily you can edit a clip, but shooting the beautiful waterfall is another reminder of the IP68 waterproofing.
The second starts off with a quick peek at Split screen mode, but the videos main focus is low-light photography. The Galaxy S9 duo can snap four shots and combine them into one bright, low-noise image. And dont forget the variable aperture f/1.5 makes the best of what little light is available.
The third video shows adult people using the AR emoji feature, which we still think isnt cool.
Source (in Korean)