s/teach/be petty/. Nobody cares about a method name and if I care, I can send my own cleanup change later instead of holding up work of others. A good compromise is to approve and still suggest a different name in comment and then trust competence of my coworkers to decide for themselves.
On the other hand, if someone is loading images on a main thread of a UI app, teaching is a primary priority compared to getting the change merged. Obviously they are misunderstanding big parts of platform they are developing for and, until I get them up to speed, they will have a hard time being productive. So even if it takes an extra week, it's important that they learn the best practices and how to apply these in specific cases.
I am absolutely against mind games like asking vague questions and holding up work until the author gives me my preferred answer, neither of us have time for that.