I cannot tell for sure, but it does feel that way.
Not only cosmetic companies but "trends" and other things that happen in the real world do affect that, for example: say that this year a hairdo and X style of body is going high, the person with these characteristics will definitely win.
Plus there is a lot of rumors regarding companies that want to use a determined model for their advertisements, so they "ensure" that the woman in uestion will be the winner.
I truly do not believe any of these competitions as there is a lot of favoritism going on.
Sometimes you clearly see that the winner did not win because she was the most graceful or beautiful, there is a lot of people paying and changing the scores, that is for sure - at least to me it seems that way.