Sam and Francis each read a different newspaper article. Sam's article said that there was a newly produced element named "copernicium", and Sam came to have a desire that he expressed by saying to his agent: "I want you to buy me a pound of copernicium." Francis' article said that there was a newly produced element named "quinium", and Sam came to have a desire that he expressed by saying to his agent: "I want you to buy me a pound of quinium." Now, there is such a thing as copernicium, but the word "quinium" is pure made-up nonsense, and the article Francis read was an April Fools hoax.
What did Francis desire? It seems we can't say that he desired that his agent buy him a pound of quinium, since the italicized words fail to express a proposition, as the word "quinium" is nonsense. Maybe what Francis desires, thus, is that his agent buy him a pound of the element named "quinium". That's a perfect coherent, though unsatisfiable, desire. (But then again, practically speaking, a pound of copernicium is also not buyable—it seems that only a few atoms have been produced.) But if that's what Francis desires, then by parity it seems that what Sam desires is that his agent buy him a pound of the element named "copernicium", rather than a pound of copernicium. But that need not at all be what Francis desires—he may not care at all what the element is named.
Perhaps what we should say is that the appetitive state picks out the proposition that best matches the structure of the appetitive state. In the case of Sam, what best matches is that his agent buy him a pound of copernicium? In the case of Francis, what best matches is that his agent buy him a pound of what is called "quinium". Francis' propositional object is a less good match than Sam's, but it's in fact the best match available (let's suppose), and hence it is the desire-magnet.
In the above "what is called 'quinium'" is short for a longer and more complex description. I don't know exactly how to formulate it, but perhaps: "dthat element which is referred to as 'quinium' in this article".