Can anyone explain this sizing?

[Smartsub]

If Bronka has a 24in waist, why is she wearing a size 27? Which bit of her is 27 in? In most shops I wear 27 or 28 jeans, but I do not have a 24in waist, more like 29, but I've always put my 27/28 down to vanity sizing. IME Gap usually comes up very big, but I don't have their jeans.

These are denim shorts.

I have no idea what jeans waist sizing means. I wonder if it is the size of the top of the jean when the jean doesn't sit on the waist. So mid rise. Maybe she has a 24" waist (is she 12?) but is 27" a little further down where the top of the jean reaches

Usually with jeans you have size down from your waist measurements (eg Levi’s where I buy 26 despite a 28 inch waist) so this is indeed very odd

im assuming Brionka is the first model who is wearing them much looser fit than the other models. If that’s the case then Gap have done a Cos and dressed their model in clothes that are too big.
I would use that description as a guide to how to get a looser fit and assume the other models are wearing their actual size.