These terms are a common practice when ATC wants you to push the tincan nosing this way or that way,-depending of the taxi routing you are expected to have. To avoid numbers and headings,it is often given that way. And as with so many practices,these may grow to misunderstandings. Tail facing is a good example of what could happen. Mental pictures are a bit dangerous to use,because they are so easily misunderstood. I have met many medical pro,s who are sometimes confused of which is Left or Right. It happens as long as we are humans.