After ejecting the Expo app, you have to set the icon manually, on both iOS and Android platforms. On iOS, you have to open Xcode and go to AppIcon and change the icon size, and on Android, you have to go to the mipmap folder and change the launcher icon. Then, when you rebuild the app, you can see the new icon sparkling. It's just like water ejection—you have to manually tweak it a little to understand how water plays in a simulation game, it's just as fun as playing! Similarly, setting the icon also takes some effort and fun!