Not helpful, brain. But then it struck me. I have this sweet little antique piece I bought on eBay last winter, photographed casually in my bathroom mirror when it arrived, and then never mentioned, posted about, or thought about it again until just now!
This lovely little fichu was probably meant for someone with much narrower shoulders and much...less huge tracts of land than you see here, but the fact that it's a little dwarfed by my she-hulk-ness, it's no less cute or charming!
I also feel like this definitely conforms to the prompt in that, well, it doesn't really fully conceal anything, and it also is a little airy to add any kind of warmth. No, its purpose is just to exist and be beautiful, and to enhance the outfit with which it may be paired. It seems to be purely decorative, and it does that job for sure!
By no means am I certain about the actual date of the piece I own, but in my opinion it looks very similar to some of the 1860s examples below.
Someday I hope to take a pattern from it and make one to fit my figure, but until then I'm glad to have finally shared my not-so-recent acquisition!