When you teach Sunday school, what kind of attitude do you project? Such a question may seem to suggest that we should act hypocritically, but that is not the intention. Rather, this question is meant to recognize that we all have a "public" face and a "private" face.
With this understood, what kind of public face do you show? Is it all business? Do you demonstrate such a great passion for presenting the lesson material that you do not show a concern for people? Obviously, both are important. As the teacher, you give an example to your students of being serious about interpreting and applying God's Word. But if you are so focused on the text that you don't take time for the people, you will miss out on a great opportunity for ministry. It should also be noted that some may take caring for people to an extreme with the result being little or no study of God's Word during the class time.
Is your attitude positive or negative? One preacher was once asked by his wife why he was so unhappy when he was preaching. The preacher didn't know what she was talking about - he wasn't unhappy or mad about anything. But he did not have a pleasant smile on his face, so it appeared to his congregation as if he was upset about something.
Does your class know you care? How do they know this?