As you can see, one of my submissions has the orange star while the other one does not have it. Furthermore, there is an upvote button on that item too.
Out of curiosity I clicked the upvote button and it looks like the vote registered and now the item shows the orange star.
Oh, the link is clickable!
Notice the id variable in the query string, its going to be the id of the orange-starred submission. You can change it to the ID of another item on that page, and the star will "move" there.
Its very handy on comment pages, because it lets you see your comment in context very easily.
Edit: I didn't mean this to be offensive. Is the downvoting because of inaccuracy or tone?
This feels similar, but I have no specific knowledge of the internals, and speak without authority.
Probably out of date though.