That is just done for humiliation/domination. How pathetic must you be to be changed into a diaper that someone else wets in; even if just a little bit? or "we know who wears whose wet". This can be done some previus time and let the diaper start to smell if it is a thick diaper and will be worn for some time. Yet another thing is to change the little one for bed a couple of hours before bedtime so that the diaper will have been wet once and the little one put to bed in a wet diaper. Nothing shows disrespect like being put to bed in a wet diaper since it shows that you have such disrespect as to not change her into a dry diapers. It is usually done to a little one who is overly proud but can be done for any other of the character traits like being babyish, whiney, disobedient, overactive, forward, gossipy or trollopy as well as proud. This last is special. How can you be proud in a baby-short dress, skirt or babydoll, in thick diapers and rubber panties that will show if you move the wrong way and just everyon will want to feel them, and you smell a bit, showing you have no control over you own body?