 So you don't understand what facing front islands do, not a problem. This is the exact same thing as facing front all, except it only applies to faces that are attached to the object you left clicked. You see how this top part is not connected to the main object? That is because it is separate, which ZBrush considers to be an island. So even though it has faces that are facing the camera, it's not part of the island that I clicked on, so nothing's gonna happen to it. Conversely, if we left click on the island, all the faces on the front of it will have actions applied, but since it's not connected to the big one, nothing is gonna happen down there. Hope that helps. Man, as always, hope you have a fantastic day, and I'll see you around.