Yeah right a 2 lol
Probably as someone said, when the waist is altered that's a two.
I'm a ten (6 us) cos of my boobs and my butt, and yeah if i tailored the waist it would be a six (2 us). But i swear for the majority of women with an hourglass figure, or pearshaped, or even top heavy, the same would apply.
I would actually love to own a couple of the dresses, but the bids are probably way too high.