Why can't we hide shoulders on costumes?

marcbf

I recently acquired the Mercymother's Attire costume for my characters and while I'm quite happy with it I wanted the shoulders (well, *the* shoulder) to be hidden. So I enabled the "Hide Shoulder" option, but nothing happened. I was a bit surprised because "Hide Your Helm" works very well with e.g. the Shrike's Nocturnal Frock costume. Am I doing something wrong or does it just not work? If the latter, why?

Dragonnord

Because costumes work as only two pieces; head as one piece and full rest of the body as the other piece.

You can confirm that when you dye a costume.