Activity items identity themselves as `Image`

![screen shot 2014-08-19 at 16 48 09](https://cloud.githubusercontent.com/assets/109850/3968586/4c4af5ee-27b8-11e4-9fe4-4b8a5fcdf06b.png)

Can we add a test that validates that the metadata is being set correctly for a library with 3 items (document, link and file)?