From chapters 2 - 4, we see the arm, a blank robotic arm. but in chapter 5, we now see additional parts to the arm, (the jester sleeve) and we have never seen anything related to a jester in the franchise. now, the images show the two differences. We all know that the Prototype Builds it's body off it's victims/dead Toys, including spares. (Kissies arm, Huggies Arm, Mommies Arm, Catnap's fur on it's back) but we've never seen that sleeve on the prototype. meaning, there was a jester toy in the factory, that we could have seen, but the prototype killed. we can get a rough idea on what the jester looked like, and by the looks of things, it would have been as big as huggy. We also know that Mob Entertainment puts details like this in there, as a hint for future chapters. we already have confirmation on Chapter 6, (final Chapter) and since we now have this tiny detail, could this mean that we see another jester in Chapter 6?