This is an astute question, the result of excellent observation; clearly you are an individual of singular intelligence and insight. I sit in awe of your skills.
The autobun is a conscious construct on Wife’s part, one she dismantles each evening as part of her pre-slumber ablutions. For this reason, in bedroom depictions, the autobun is notable by its absence.
To learn more about the origins and mystique of the autobun, please consult the following online resource: http://www.awfulpicture.com/2015/01/awful-pictures-imaginary-words.html
I thank you for your inquiry.