An embodied interactive agent has a virtual body that is generally drawn by CG animation. We intuitively assume that the agent's body primarily expresses non-verbal messages, or symbolizes its social characteristics through its appearance. However, we have not objectively elucidated the expressive competence of an agent's body beyond the conclusions of our empirical and subjective intuition. Therefore, it is necessary to explore scientifically how users regard the functional competence of an agent's embodiment. Do users attribute the intelligence of an agent to its virtual body? We investigated how users physically interact with an agent which is merely a virtual entity drawn on the display by CG, through "showing" something to the eyes of the agent, "listening" to something from the mouth of the agent, and "speaking" something into the ears of the agent. However, such interaction does not necessarily attribute the intellectual processing function to the agent, and this issue is explored through two psychological experiments.