From the pics, it looks like a mild case of fur mites like Thor had when we got her. Many buns may have a low level of fur mites, but when they get too many the skin starts to look flakey. The flecks are probably a mix of dandruff and actual mites. I’d recommend getting her checked out by a vet!
Good news is that these are easily treatable and humans are not susceptible
My vet prescribed Revolution for kittens, it’s a topical medication applied to the skin between the shoulder blades once a month for about 3 treatments. Once she is being treated you’ll want to do a good vacuum of her enclosure to reduce the number of mites around.
**Safety note!** The active ingredient in many mite treatments for dogs and cats, Fipronil, is HIGHLY TOXIC to rabbits. It’s the main ingredient in Frontline and a few other brands. If you have a rabbit savvy vet they will know not to prescribe this, but it never hurts to be safe!