A representational metaphor transfers the likeness of a complete scene rather than merely substituting one noun. The borrowed configuration should fit the intended situation as a whole. A superficial match in one detail is inadequate if the essential structure of the situations differs.
The listener should be able to identify what situation is pictured and what comparable pattern occurs in the intended situation.
Word-by-word paraphrase alone will not explain a representational figure; its quality lies in the overall arrangement formed by several linked details.