Comment 3 for bug 1437026

There is nothing in the spec that says the icon should be different from normal; it just says "Application icon to identify where the message has come from". <http://goo.gl/KIrWzF> We couldn't reasonably expect every app that might appear in the Notifications list to package a symbolic version of its own icon. And even if they did, it wouldn't be a good idea, because it would be harder to distinguish apps in the list.

(System Settings shouldn't be showing up in the Notifications menu in the first place, but that's a separate problem.)