What makes an influence manipulative and what makes it wrong are the same thing: the manipulator attempts to get someone to adopt what the manipulator herself regards as an inappropriate belief, emotion or other mental state. In this way, manipulation resembles lying. What makes a statement a lie and what makes it morally wrong are the same thing – that the speaker tries to get someone to adopt what the speaker herself regards as a false belief.
When a branding expert proposes using untrue terminology to market an idea, that is being manipulative. That is not being persuasive based on facts or logic.