They also use pretty similar examples: a classic one is to think of an being on the other side of the galaxy thinking about Winston Churchill. Even if they have the right image, they even happen to think the right things about where he lived, what he did etc. it seems that they don't actually succeed in referring to him because of the lack of a causal link.

(They could be referring to all objects of class CHURCHILL, but not to our own, particular Churchill, although he happens to be such an object.)