A thing may be the icon of an idea, but that thing is always its own meaning.
An architectural design is the Nth order schematic of an architect's concept. The building itself is the first order model.
What does a book mean? A summary is a schematic; a dissertation, a ramified accretion of interpretations. But the meaning of the book is exactly what it contains.
A woman asks the vendor what a certain exotic fruit tastes like. He cuts it open, hands it to her, and says, "like this."