I think that advertising aimed at children is an easy way for companies to make money thus distributing it to the economy in the long run ( these are not big considerations save for Barbie and Play-dough) . Plus if the parents where stern enough with their kids and knew how to say "no" to things, this wouldn't be a problem in the first place.
But it would also have some cons. happening to the children because what if they are getting used and that would make them feel shamed for their whole lives and what if they get abused while they are advertising an advertisement while their parents are away. Add on childrens doesn't know how to complain.
How is it the advertisements fault of the child gets abused at home? I could understand if they get bullied at school for not having the latest bat man action figure or the latest barbie doll but the child could always express that to their parents and either the parents take that issue up wit the school or just buy the kid what he or she wants to solve the problem. you cant get mad at a TV advertisement for advertising. That's like being angry at a sweater for making you hot in the summer.
In the case of a Diaper company you cant ask a baby to take off his or her cloths, the most likely wont understand you or wont have the ability to do so, also how on earth could they not have parental consent? they could not have the child there in the first place if they did not. furthermore if they' re doing an experiment that requires babies to wear the diaper these would most likely have to be trained professionals with valid credentials in order to get to that step in the fist place.