metaphors can create similarities

"Our view that metaphors can create similarities runs counter to the classical and still most widely held theory of metaphor, namely, the comparison theory." (#60 2646)

Metaphors can be based on similarities

"Metaphors can be based on similarities, though in many cases these similarities are themselves based on conventional metaphors that are not based on similarities. Similarities based on conventional metaphors are nonetheless real in our culture, since conventional metaphors partly define what we find real." (#60 2660)
"Though the metaphor may be based partly on isolated similarities, we see the important similarities as those created by the metaphor, as described above." (#60 2663)
"The primary function of metaphor is to provide a partial understanding of one kind of experience in terms of another kind of experience. This may involve preexisting isolated similarities, the creation of new similarities, and more." (#60 2666)

"Briefly, an objectivist would say that objects have the properties they have independently of anyone who experiences them; the objects are objectively similar if they share those properties. To an objectivist it would make no sense to speak of metaphors as "creating similarities," since that would require metaphors to be able to change the nature of the external world, bringing into existence objective similarities that did not previously exist." (#60 2672)