Engineering managers may technically mentor their individual contributors but it benefits from delineation.
Managers naturally mentor on business and execution matters, and may sometimes share opinions on engineering, but engineering managers also possess a wealth of expertise that goes unused in that arrangement. Setting aside time to specifically mentor on technical topics offers individual contributors an opportunity to learn and explore a wider skillset than their immediate focuses would permit and also grows the working relationship through deeper sharing of philosophy whereby a contributor may be better enabled to meet the needs of harder-to-articulate requirements.