The fog covers everything, the branches only poking through when Lydia walks close to them. It's a haze. She's looking around, constantly, arms wrapped around himself. She's never liked the woods during the day and at night? After being lost in them for days she doesn't ever want to go back (but at least she's clothed). In the fog Lydia can't see her footing, her foot catching on a branch sticking out of the ground, causing her to fall with a small scream as she does.