So, here's Claudia's attempt. Not a disaster, as she says, but the first step in the journey. You can see, though, how little lift to the chest there is in both these positions. Interestingly, there is quite a bit of ashtanga-blogging on the subject. For instance, Yoga in the Dragon's Den:
Kapotasana teaches us something about navigating the sufferings of daily life as well. Whether we like it or not, life throws unpleasant things at us, things that we can't just wish away or depend on others to take care of. We can choose to play into the drama that these things tend to evoke in our minds, and make the suffering bigger and badder than it needs to be; or we can do what needs to be done, breath, and go through what needs to be gone through with fortitude and hopefully, grace.