Nina’s last line may seem like a throw away line, but how you choose to frame a concept can have an effect on how you approach it, or your mental state while dealing with it, or any number of things. Nina is being positive about John’s apparent self consciousness, perhaps instinctually, to help him reframe his quest in a more positive way. In a way she’s telling him she believes in him without actually saying it.
Branding, advertising, politics, all of these things do a version of this. It’s manipulation. Which, like any tool can be used for good or evil. It depends on who is using it.