The lock screen can now detect dark and light areas of the wallpaper and change text color accordingly to increase legibility. As you can see in the picture above, with a wallpaper that’s half black and half white, One UI 1.x uses white font color for all text, making it illegible in the upper half of the wallpaper. One UI 2.0 changes the text color in the upper half to black while keeping white text in the bottom half.
On One UI 2.0, if you have your lock screen set to only show notification icons, tapping any notification icon simply expands the notifications on the lock screen.
On One UI 1.x, whether you try to change the wallpaper from the Settings app or by pinching the home screen, you are taken to the Galaxy Store, where you can either browse through wallpapers from the store or access your own wallpapers. On One UI 2.0, there is now a dedicated menu for wallpapers, where you can see multiple options and also a preview of your current home screen and lock screen wallpapers.
You can either select My wallpapers to browse through preloaded wallpapers, select Dynamic Lock screen for setting wallpapers based on particular categories (more details here), select Gallery to use an image from the Gallery app, or select Explore more wallpapers if you want to look at wallpapers in the Galaxy Store.
On One UI 2.0, the system dialog to an app shows up at the bottom of the screen instead of in the middle. There are also more options for allowing permissions. For example, you can either deny a permission to the app, deny and tell the phone to never ask you again for that particular permission, allow the permission, or allow the permission only when while you are using this app so it doesn’t access data in the background.