Nested figures

![](http://content.screencast.com/users/tmsp1/folders/Jing/media/339f30cc-65de-4531-8f65-096fa1fe1978/00000348.png)

i could use some feedback on the ux here, i think we should definitely do the thing where we only have a few canned image sizes, that will make this way less annoying to use.