A poetical 'metaphor' (to use this term extensively) is of course not real in the scientific sense but it is also more than a mere symbol. If you cannot at least somehow immerse yourself in it- or project your imagination into it- as if it were real, then you won’t be able to use its full potential which partly is constituted of the communication and relation of things that are too complicated or intangible to be expressed in any other way. This characteristic it shares with mythology and also with the anecdote, the little story from ones own or anothers life.
Recently I have heard an interview with German-born physicist Hans-Peter Dürr (not to be confused with ethnologist Hans-Peter Duerr) who explained this higher function of poetry, myth and story very well when describing his cooperation with Werner Heisenberg in the field of particle/quantum physics.
When any of them would disagree with the other or when they would encounter difficulties or dead-ends in their research, they would sit themselves together and for example, Heisenberg would say something like: 'My problem with this or that (technicality) is like this:' (And then he would tell a story from his life), whereupon Dürr would reply: 'Ah now I see your point but then to me it feels additionally a bit like this:' (and here he would tell a little story), and so on. By this method they would, Dürr stated, know much better than by any other what their interlocutors’ reservations meant in the context of their research.