Objects have innumerable attributes, but not all are relevant in a simile. A speaker may select a few precise characteristics while setting aside the rest, or may require several features together to establish a distinctive image.
If the shared respect depends on three features, identifying only one does not reveal the complete comparison. Similarly, when the absence of a feature is essential, a list of positive qualities alone is inadequate.
The crucial distinction is between all the properties an object happens to possess and those selected for the rhetorical comparison. Only the latter define its intended point.