phil....thanks for the explanation. What I also meant.....the back glass needs to line up correctly with the front glass to work properly...correct. If so if I turn the front glass so that the top in landscape style is turned to the top in portrait style...then both glass elements are in a different position to each other...unlike in landscape position. Do I make sense? I guess I don`t really know how the glass at the rear works......hmmm. Maybe someone can explain.