One of the features of Android 13 is the implementation of themed app icons.
You can enable them by long pressing on your home screen, going to Wallpaper & style and selecting Themed icons.
As for this application you will see the following screen icon:
And the only icon:
Next we can add monochrome tag in mipmap-anydpi-v26/ic_launcher.xml with the same drawable as for foreground.
<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
<background android:drawable="@color/brown_200" />
<foreground android:drawable="@drawable/ic_launcher_foreground" />
<monochrome android:drawable="@drawable/ic_launcher_foreground" />
</adaptive-icon>
The icon will be completely flooded:
Next we can copy @drawable/ic_launcher_foreground and remove the paths.
<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
<background android:drawable="@color/brown_200" />
<foreground android:drawable="@drawable/ic_launcher_foreground" />
<monochrome android:drawable="@drawable/ic_launcher_monochrome" />
</adaptive-icon>
The icon will become optimal and more detailed:
For more detailes see the commit, where current doc were added.