On your Samsung Galaxy S8 around certain apps frames are placed, so you can recognize them better. If you only want to see the app icon without a frame, you will find the appropriate setting in the following Android submenu:
From the Home screen, navigate to the app menu and click on "settings"
1. Tap Display and scroll down to "Symbol Frame"
2. Tap the entry and you will enter the next submenu
3. Select "Symbols". Finished!
From now on you will only be able to see the app icons without a frame appearing. This makes the system of the Samsung Galaxy S8 optically slimmer.