Exactly what it says on the tin, a storage for designs made on the loom. Maybe one you can save to your computer, maybe that you can even upload from your own files to provided it is the correct file type.
Also, an online repository with other players’ uploaded loom designs, so that you can use other players designs in your own home, edit them as you wish, and so on, preferably in-game.
However, if the former was implemented, the latter could be utilized with alternative sites or even on this Discord.
Mostly, I just think there should be more loom options, as it stands it is difficult to make work properly for more complex designs, like one I will post below. I would be very down if this was an update or DLC.