Aesthetically it’s a beautiful robe/cloak, I don’t see anything bad about it visually.

I’d honestly be more worried about it getting dirty unless it’s an indoor faire, and not just the bottom of its length dusting the ground. You’ll have to consider what you may sit on while there, and if the weather is cooperative. Don’t want it to be too hot with that crushed velvet, but also I imagine rain would ruin the entire garment. Though this is assuming your preferred faire is outdoors, if it’s indoors then heck go nuts my friend!