Metaphor is a powerful, conceptual device for structuring and thinking about an unfamiliar, new, or abstract domain of experience or knowledge (say, computation) in terms of another domain that is more familiar or concrete. We will examine the different, mostly unconscious metaphors that we use in thinking about and doing computation and design. We will look at the ways these metaphors highlight, emphasize, and enable some ways of thinking about computation and design, while disabling or marginalizing others. These reflections may point us to new ways of seeing and doing computation in design.