Spotify might be thinking to unify its desktop app and web player. App researcher Jane Manchun Wong spotted the potential redesign, which she noted looks almost the same as the web player. Controls are more or less the same, but this means it could be less confusing to jump from the web app to the desktop app.
Some users have already reported getting the new interface, but are complaining about things like not being able to sort playlists by name, song date, etc.; search for songs within playlists; or receive a warning if you're adding a duplicate song to the playlist. But again, this is still a test, and we hope Spotify improves usability. It isn't clear yet if more users will be getting the new version. Wong also mentions that lyrics are coming to the desktop, too.