With the loop closed we can now insert the spinning tool at the base of the loop. Here I have a Byrd's Dubbing tool but any bent piece of thin rod will suffice. I used a paper clip for years . They travel well and don't cause a calamity when lost or "borrowed".
By placing the tool in the loop we can now maintain the open access to the loop. If you just formed the loop and let go the thing will twist back up to the hook and you can not open it to add materials. So the tool at this point keeps the loop "open."