Despite being neck items themselves, the Turkey on Shoulder and Eternal Questioning Angel and Devil items are not visible on your player when selecting neck accessories.
(occurs when toast is both equipped and unequipped, so the toast is unrelated)
I believe this is the fading system kicking in. When the camera is near pets and other wearables it hides them. It seems the fading system is not disabled (while in the appearance editor) for those items in particular when it should be.