Mrs$.$ A: your daughter has started taking piano lessons, hasn$$t she? I envy you, because you can be proud of her talent. You must be looking forward to her future as a pianist. I$$m really impressed by her enthusiasm$$every day, she practices so hard, for hours and hours, until late at night.

Mrs$.$ B: On$,$ no$,$ not at all. She is just a beginner. We don$$t know her future yet. We hadn$$t realized that you could hear her playing. I$$m so sorry that you have been disturbed by her noise.

In this brief conversational excerpt, what communicative issue does Mrs$.$ A$$s comments exemplify?