3. It adapts YouTube videos to use the full width and height of the screen.

Most videos on YouTube aren't produced with the Galaxy S8's 18.5:9 aspect ratio, so we were expecting YouTube videos to show videos in the regular 16:9 aspect ratio that most YouTube videos are produced, resulting in black borders on either side of the video, called "letterboxing"

However, the Galaxy S8 automatically adjusts the video to display in the phone's 18.5:9 aspect ratio, making full use of the phone's glorious screen and avoiding the letterboxing effect (though it does partially crop the video).