larger avatars in embedded posts

### BEFORE
![before](https://f.cloud.github.com/assets/362783/974169/2a585e56-064c-11e3-8b79-e0e72f3aa9f3.png)


### AFTER
![after](https://f.cloud.github.com/assets/362783/974152/eb13fe30-064b-11e3-91f2-d531b4a709d8.png)