I have included a few photos, so that you can see all the asymmetry in all its glory.
The off-the-shoulder section is cut as a different piece than the sleeve-and-shoulder. Amazingly, this dress does not gape at all, no matter which way I bend and twist and turn. I am wondering if this is because the 2 bust sections are cut on opposite biases?
I'll pop the details in a pattern review, for anybody who has this pattern lurking in their collection.