Why are implicit and imaginative metaphor treated as two aspects here?

Implicit and Imaginative Metaphor: Definitions, Core Examples, and Analysis

• Implicit metaphor omits only a particle while imaginative metaphor omits only the shared feature
• Implicit metaphor openly names the source and imaginative metaphor suppresses it
• Both are different senses of the same isolated word
• One conceals the simile; the other ascribes a source attribute