I find this to be a really appropriate "model" pose. It's like the "butt blush" reflects her own blushing at such a strange pose. While there's nothing unnatural about the pose itself, the feeling of one watching, let alone taking pictures for her perched upon one, would be a rather embarrassing feeling, with the blush sort of reflecting that.
Really glad we get to see more from you; it's been far too long. :)