Abnormal Behavior. Chicken spread out on top of sick one in nesting box.

[SylvieXandra]

One of our chickens (a frizzle) has no feathers and tends to hide out in the nesting box. For the past week, one of the healthy birds has been laying on top of her, wings and tail completely spread out to cover her. They are the same age and have been raised together since day one. I’ve attached a couple videos. I’m very worried about them. This behavior is NOT normal

 

[DobieLover]

The black one is broody. I have no idea why she is sitting on the frizzle. Is that the only nest box?
Were the frizzles feathers broken off? Is she the only one of her kind in the flock?

 

[FrostRanger]

Dunno what's wrong, but the one covering her is too cute!
Does the frizzle have any other symptoms? Is she possibly getting picked on by any of the other birds?