TV Pics for Reddit is an app which allows you to browse images posted in subreddits on reddit.com.
The main screen will let you edit the list of subreddits that will be available to view on your TV.
Once you select a subreddit to view, you simply need to swipe anywhere on the touch area of your remote control (top half of the remote) in order to go to the next or previous image. You can also just press the play/pause button on your remote control to advance to the next image.
Please note that subreddits are public forums, and while moderated, some may contain images that may be offensive to some people. Please keep this in mind as you are using this app.