Petite women come in all shapes and sizes. Manufacturers can forget that. Or be completely unaware of it.
My experience of petite clothing in the UK has been that they seem to be made for proportionately petite bodies. Yet how many human beings have proportionate faces, much less proportionate bodies? Petite bodies can have wider hips, longer arms, shorter torsos, bigger busts or larger bums than you’d expect for their height. Different kinds of petite women deserve to be catered for. They deserve to be able to buy clothing off the rack that at least comes close to fitting well without requiring any alterations.