A good use of an analogy would be, for example, Otto von Bismarck’s famous quote that laws and sausages are two things people shouldn’t see being made. That does a good job of conveying the point that making laws is an ugly business and the public would lose their faith in government if they could observe the lawmaking process. In this context, Bismarck is just explaining a new idea to us in a memorable way. That is a good use of analogy.
