The icon is in the repo covered by the AGPLv3. Signal-Desktop does not have a CLA that would enable them to license the built binary anything but AGPLv3, as the

The icon is in the repo covered by the AGPLv3. Signal-Desktop does not have a CLA that would enable them to license the built binary anything but AGPLv3, as they do not have sole copyright over the code. They themselves are also bound by the AGPLv3.