Seasonal gear and some of the crossover gear go in there. The oddest thing that goes in there is the patriot's choker, available form your GC.

Things I think should go in there: everything! When items are put in they lose everything, meaning very little data is stored. It may be as simple as a checklist, which is pretty much how collection based fashion systems work in other games.

At the the very least ALL the job sets and all the crossover gear, or have the Glamour dresser access the calamity salvager.