In the 80's and early 90's the sample sizes provided for actors/models were sizes 6-8 and 10. The sizes used to be 6/7, 7/8, etc... It's quite a drastic difference when you look at the 0-2 now. R. Witherspoon she lost weight from a 4-6 so she could have more choices in clothing. She could not fit into anything provided now.
I think what people see, through media, has affected views. At one point models like Twiggy were a rarity. Now they are all twigs.
I would love it if thy showed every size, without the attached labels.