Again, lead vs mentor. The mentor/mentee relationship isn't usually a formal one enforced by your workplace — it's one built over time, when a less experience

Again, lead vs mentor. The mentor/mentee relationship isn't usually a formal one enforced by your workplace — it's one built over time, when a less experience member of the team trusts somebody more knowledgeable, and seeks them out for advice. Any such suggestions are usually meant to be taken as as side projects, not as work tasks. A lead giving you a task like that is probably inappropriate, because they should be focused on producing results. They should, instead, try to find low-hanging fruit that's within your reach. For a mentor, however, it's entirely appropriate to tell you to do something "useless" because the real goal isn't the end product, but the learning experience.