Looks like it just displays your flair and rep. Judging from the screenshots (and the date on the post - over two years ago) it was written before the super collider. Since gadgets are just HTML it could be updated to show the super collider - I might even use that myself.
That gadget is of no big use. However if you want to see something enter your UserId number. Click on your userId in the top , this will take you to your profile page. There in the top-right you can see your user-id. Enter that in the gadget and it shows up your reputations