You can browser your river in either one the following views:-

List View

Drops View

Photos

If there are any photos grabbed from the channels your river is picking information from, they will be shown in the photos view.

You can also filter drops in your river based on channels/sources

The "Channel" menu can be found on the left side menu.

Select the channel you'd like to filter your drops by, and your view will be populated with drops from that specific source

The number of drops per channel is also indicated adjacent to the source name. e.g, in the illustration shown below, there are 708 drops from Boing Boing in this river.