What is happening here? Jesus is seeing to the very core of Peter's identity and drawing it forth. Whatever others may have thought of Simon, regardless of how Simon may have seen himself, Jesus sees to the truth of his identity in God and names it: you are Peter. Whenever we place ourselves before the look of Jesus, the same thing happens; our full truth is laid open to view, and we find meaning, direction and destiny.
In other instances, the look of Christ will bring us to an awareness of something lacking in our discipleship and thus summon us to new depths of conversion. Not easy. Consider what happened when a rich young man came to Jesus and asked what more he should do to inherit eternal life (Mark 10: 17-22). Jesus, we are told, looked at him and told him that he must sell his possessions, give his money to the poor and follow him.