(at around 1 min) When Wilbur says to Ed that "Zsa Zsa Gabor is coming over to see you", and right when Ed says "who's he" a white line can be seen angling down in front of Ed's nose towards his chest. Perhaps this is the signaling line used to let Ed know to move his lips. In this case it looks like it could be connected to a front leg. Other times (in other shows), a clear line can be seen coming down along Ed's jaw when the bridle is not on, and still other times a black line can be seen leading down from the side of his jaw into air.