Maybe I'm just extremely inattentive, but I have never seen these cookies floating around in my milk before today, and this update has been out for a while now. I can click and drag them around, and they bounce a bit. Do they mean something?
Edit: After a little code-digging, I found out what caused this. It's a 1/10,000 chance when the game loads. You can activate it in the console by setting Game.TOYS = 1, and you get one of two types of toys, randomly. This is neat, though I wish my luck gave me something more useful, like a golden sugar lump, haha.