why do children stop being cute?/why do we get ugly during pubescent years?

I noticed that 5-8 years old is around the time where children are very cute and just not ugly but they start to turn 9,10, 11 and they just start looking really ugly. It happen to me. I just can't spot it, what is it that made them lose their cuteness. They don't look anywhere near an adult but they also aren't babyface cute. What is in their face that makes them look...so bad and not cute anymore? and please don't say their attitude. I'm merely talking about pictures. you take an off guard pic of a five year old doing something and it's photogenic and very adorable. you do that with an 11 year old and it doesn't have the same effect.