Everyone knows that Samsung make their phones’ UX different from other Android phones with Touchwiz. And this time, Samsung decided to add a rounded square around an app’s icon, which I think they take customization a little too far. If your Samsung phones are running Android 7 Nougat, you will recognize this new change.
The image below shows how owners of Samsung Galaxy series running Android Nougat see the icons by default. Each icon is scaled down and surrounded by a white rectangle.
This feature is turned on by default, so what you need to do is disabling Icons with frames setting. Access this setting via Settings > Display > Icon frames then choose Icons only to remove the frames.
A developer can remove this effect by adding a meta-data within application tag in the manifest file.
<meta-data android:name="com.samsung.android.icon_container.has_icon_container" android:value="true"/>