I haven't seen a way to do this, apologies if I just haven't figured it out, but there doesn't seem to be a way to sort items in a particular way within gallery categories other than switching between sort by name/sort by item ID/etc... it would be immensely helpful to be able to drag-and-drop sort things in galleries like we can do with pet treasures, or something like that!

For instance, I have a gallery dedicated to pop culture reference/themed items, categorized by types like "TV and movies" / "cartoons" etc, and some of them are kind of obscure at first glance, and would make a lot more sense if I could group together things from the same movie/etc ("why is a clarinet in here?" [puts it next to the spongerob] "oHH, squidward!")

there isn't a way to do this it would be nice