When you reflect another person's underlying feeling in a statement, you are engaging in:

Reflecting feelings or reflection of feelings

Explanation:

When someone reflects on another person's underlying feeling in a statement to that same person that they are engaging in reflecting feelings or reflection of feelings. This is normally done by psychologist or by someone who is trying to educate someone in regards to their behavior. These underlying feelings are often reflected through behavior, way of talking and body language and therefore, can be an important tool for parents and teachers to evaluate children and assist them in understanding and regulating their feelings.