Though I know very little Russian, I know enough to say that "how" and "pochemu" do not map 1:1 -- If I asked, in English, "how is this cardboard box flat?", the natural response would be "it's designed to be flattened" rather than "someone folded it down", but the natural response to "pochemu" would be the second. The full translation that was given would be necessary to disambiguate.
