Currently the Smart TV app (at least on Samsung) does not have a play queue. You can play an album and sometimes playing one track will pull in other tracks to play. But you can't add tracks to play next while one track is playing. It's pretty common to search for tracks while you're already listening and when you come across something interesting you want to queue it without interrupting the current track, like you can in the desktop version.
So the idea is: add a play queue to the Smart TV app.