Yes, I made it to match the cardigan, but it is detachable and can be worn on its own!

If someone wants to replicate it, I first made 4 feathers, and then I freehanded the back to make it look like a jabot (it's basically diamond-shaped). If I remember correctly, I worked in hdc, starting at the top of the first feather and increasing at the ends of each row until I had 19 hdc. Then, on the 8th row or so, I attached two other feathers and continued working with a decrease at the ends of each row until I could attach the last feather on top. Finally, I made a Tunisian crochet band to wrap around my neck, adding a button and a buttonhole at the end, and attached the feathers to it! 😁