A speaker may consistently produce correct Arabic yet address young beginners in inaccessible specialist terminology or explain elementary points to experts at needless length. Their linguistic competence may be strong while their audience-sensitive expression remains weak.
A different speaker explains the same subject fully to novices, briefly to specialists, and with appropriate reassurance or emphasis to a doubtful audience, all while remaining linguistically sound. This exemplifies a developed faculty of balāghah.
The distinction is not a pleasant voice or loud delivery. It is the ability to combine linguistic soundness with contextual suitability.