A leaked shot of the box art for Theatrhythm Final Fantasy, courtesy of Twitter user joshua_x_, reveals a curious logo for something called the "Nintendo Network." Both name and logo appear to be brand new, indicating that Nintendo will be rebranding some aspect of the 3DS's online services between now and the game's February 16 launch.
As Theatryhthm is a single-player only title, it's unlikely that the service represents some new push for a unified online multiplayer network.
One plausible explanation is that the new brand will be tied into paid DLC. The back of the Theatrhythm box touts the game's support for downloadable content, with a fine print notice that it will need to be purchased separately. That likely makes Theatrhythm the first game to offer paid DLC on the 3DS, following a December firmware update that introduced the feature.
Of course, until Nintendo makes some sort of official announcement, any speculation will remain just that. With less than a month until Theatrythm releases in Japan, you can expect to hear more about the "Nintendo Network" in the very near future.