Wei Wuxian scooches up to it and sits there like he is sitting at an edible table. He reaches down and pulls off another piece, starting to munch on it. Eventually as he eats he does seem to be getting a little bigger,which makes it easier to eat even more of the cookie without getting full.

"It's working!" There is no mistaking the size difference now as he moves to sit on the bed next to Lan wangji with the cookie in hand. "Still can't reach anything but at least I can't be stepped on."