Fix avatar display on mobile profile

Before:
![profile-picture-before](https://f.cloud.github.com/assets/930064/1556018/48220350-4ea5-11e3-8638-c51e940cb18b.png)

After:
![profile-picture-after](https://f.cloud.github.com/assets/930064/1556019/4ccaf95c-4ea5-11e3-8bf8-dbee4d362ebd.png)