In “khadduhu yushbihu al-ward” (“his cheek resembles a rose”), the cheek is likened to the rose. This is not merely replacing a word with its synonym. A relation of resemblance contributes to the meaning, and both the compared subject and the comparison object must be identified.
Compare “His face is red,” which states the color directly, with “His cheeks are like roses,” which invites the hearer to apply appropriate qualities of a rose, such as color or freshness. The second relies on the understood relation and context.
This is not yet the detailed chapter on tashbīh. It illustrates why a movement from a given meaning toward an intended quality may be more layered than mere lexical substitution.