Houdini refuses to nap in cot

I put ivy down in her cot for a nap. She objected but I let her cry for a bit to see if she'd settle- when I went back she was sitting up at the other end on the cot with one arm out of her sleeve like this.

I have no idea how she managed either of these things: she can't get to sitting by herself yet and the t-shirt isn't even particularly baggy. She seems pleased with herself though.