This may well be a play on words. Is Gazelem the seer stone or the servant? It is difficult to tell from the passage and depends very much on the placement of a comma in the sentence. Perhaps it could refer to both.
It is interesting to note that when Jesus called Simon Peter to the ministry he said: “Thou art Simon the son of Jona: thou shalt be called Cephas, which is, by interpretation, a seer, or a stone” (JST, John 1:42).
Though this name or title of Gazelem may be used in regard to any seer who utilizes seer stones, it seems in this instance to be a direct reference to Joseph Smith the Prophet.