It technically doesn't, there's a texture with some old microsoft windows on the actual model, but it doesn't show in the game. If you want something to show up, you can use ERROR's HUD shader, though.
the only problem I'm getting now is anyone rotation of the avatar's pet, whether by animation or just the dynamic bones, skews the scale of the pet, so it looks wonky temporarily (til it stops moving). the only solution to this is to make an empty game object at the location you want the pet, then have the pet sit at the root of the avatar with a fixed joint connecting it to aa rigid body on the empty you created. This fixed the scaling problem.
Scratch that! Turns out the dynamic bone limiter just breaks this. Turn off the limiter in performance options and it should work like a charm again (have yet to test this out on the prefab specifically, but it worked on my own tests)
seems something's broken this prefab as of a recent update. works wonderfully in Unity but does nothing when in VRC. Sad, I had a great plan for this. Hope this gets an update, it's super useful!