Children who are not yet operating at the level of fully conceptual beings are often said in Objectivism to have a concept implicitly. When it comes to art, I think that there are similar questions. But back to art. I think that Rand's distinction between the three kinds of judgment can perhaps shed some light on the question of show vs. tell. This gets back to my speculations on aesthetic vs. logic.
Philosophy is the conceptual presentation of ideas about reality.
Now, it seems to me that morality or ethics is a conceptual presentation of ideas. The introduction of telling or teaching into art debases art by making it propagandistic or didactic. Or so it seems to me now. Well, I ask you introspect.