It's definitely the 'tits and ass pose'. Why choose whether to focus on just one, when you can snap the spine to show off both in the same picture? Just draw any random featureless squiggle that hypothetically connects the two, because it's not like anybody notices any part of anatomy besides the tits or the ass, right? If you can't make the two connect in a way that looks remotely human, don't worry, just throw a belt on her - it confuses otaku like stripes on a zebra.
