Ahh, I see. (Does anyone really notice this? Not me.)
I tried to create the launcher icon with:
https://romannurik.github.io/AndroidAssetStudio/icons-launcher.html
but the result is almost the same (even with a circle)
.
Btw, also the same result with Kodular.
Left: circle (192x192px), right square (192x192px):
Background transparent:
