It seems to be a blackmail note. Of the usual sort - deliver to me what I wish or else. Specifically, it requests shards, or sigils.

[ Javik spoke of sigils says Curufin quietly, eyes narrowing. And shards... to ask for such bodes ill ]

To take one's sight speaks of strong magic indeed. And I would be leary of any offer to return it, when it would be just as easy for the Fox to continue to dangle it over your head.