Answer: What represents a can, it´s what´s inside of it, not what´s made of.
Explanation: Usually when you´re trying to show others what your texts or speach talks about, it would be enough if you are just clear and concise on what you say. But you always have to have a last ditch effort/resource, and it also counts as a default option: the clearity of your text. It has to be undertandable by people of all ages in order to maintain the professionalism of your work.