I had a baby hatch similarly to that... I also thought it was odd as I've never seen that much down in the comb area. I looked it up and found something about that being possible sometimes with pea combs. Perhaps it's one of those odd pea combs or the pea portion of the walnut happened to have that trait for whatever reason (if that is possible)?
This was the article I found that mentioned hairs being possible in the comb area with pea combs. It's mentioned on the first page within the first paragraph on Pleiotrophy. Interesting article for sure!
https://www.chickencolours.com/wp-content/uploads/2019/12/What-Wattles-lowres.pdf