It's because it's got a smooth inside.. and it's probably very long. The hose out back is all crinkly and short would probably sputter and shoot ice everywhere instead of poop frost sausages. ..But it doesn't snow here anyways, so whatever. I won't get to experience the magic.
This is just supercooled water instantly freezing once it hits the open air. I've had this happen once with a water bottle in the freezer. I left it in there for a while, opened the door, and it was still liquid. I then picked it up and instantly it froze right in front of me.