Final answer:
The negative side of improved metacognitive skill during adolescence illustrated by an imaginary audience, which is a form of heightened self-consciousness where teens believe they are constantly under scrutiny.
Step-by-step explanation:
During adolescence, metacognitive skills advance and adolescents develop new thinking abilities, including abstract reasoning and improved logic. However, a negative side of improved metacognitive skills can manifest as an imaginary audience. This is a form of adolescent egocentrism where teenagers feel that their actions and appearance are constantly being scrutinized by their peers, even though this is not the case. It represents their heightened self-consciousness and the belief that others are as interested in them as they are in themselves.