Jehovah Witnesses, who did Jesus tell?

The Watchtower, Jehovah Witnesses, claims to have been chosen by Jesus to be the "faithful and discreet slave". Forget for a minute that the verse they get this term from was taken completely out of context. Since Jesus came invisibly, who did he tell that he had chosen the Watchtower organization that they would be this "faithful and discreet slave" and God's organization?