Put the meaning into your own words.

Her contemptuous dismissal ended any chance of a useful discussion.

Cam sounded arrogant when he announced that nobody else in the studio could match his judgment. After one minor suggestion was accepted, he became smug, looking excessively pleased with himself and treating the choice as proof that he needed no improvement. His contemptuous dismissal of a colleague's careful question suggested that he considered her unworthy of serious attention.