As in other metaphors, compound metaphor needs a clue showing that the original scene is not being asserted literally in the new setting. The surrounding discussion of choice and hesitation may establish that a person is not physically stepping forward and back.
Two uses of the same sentence:
1. Description of a walking person's actual steps — potentially literal.
2. Address to someone hesitating over a decision — potentially representative metaphor.
Neither the popularity of the phrase nor the presence of motion words alone proves figurative use. Context determines which situation the complete image is being applied to.