Smugmug has always been a problem on Roku. Smugmug staff are Apple Fanboys and never give much time to other venues. There was an earlier Smugmug app on Roku (seems to be deprecated now) which was dreadful.
I recently found the Roku Photos App on my device. It promises to "Explore photos from your favorite service on your TV. Link your Roku player to your service account . . ." When I go there, even better, it already seems to find public Smugmug photos. But when I go to "Add Account", only my Flickr account (I have the Flickr app installed) shows up. Very frustrating. Clearly, Roku has a link to Smugmug but I don't understand why I can't link my account. Am I missing an obvious link???? Anyone successful in linking Smugmug account to this app?
I'm seriously considering creating a new Roku app for SmugMug. Let me know if you're interested here: http://survey.smugmug-roku.com