I'm not sure I follow the argument at the end. The author has given a good explanation for why our current metaphors describing the lambda calculus might not be

I'm not sure I follow the argument at the end. The author has given a good explanation for why our current metaphors describing the lambda calculus might not be applicable to aliens (requiring the concepts of direction and containment), but I don't see why, for example, the gas-planet aliens might not have their own metaphors relating to wind patterns or aerial acrobatics or something we wouldn't understand at all. There can be multiple metaphors for the same math.