Are you wanting to get back to the list of topics so that you can look at another one?
If so, most browsers support multiple tabs. Instead of left-clicking on the topic, right-click and select the "open in new tab" option (may be worded slightly different depending on browser). You can do this for several topics at a time. Then just click across the tabs, read each topic, comment if desired, and then close the tab by clicking on the X in the corner of it.
When you've read and closed all the topics you picked, you should be back to 1 tab that has the unread topics or pictures or whatever list.