If she took out a raw jade material without any jade inside, it would seem as if she was making fun of Kang Shaojie. Although Kang Shaojie might not know it, Gu Ning didn't think he was a bad man so she had no intention of teasing him.
Kang Shaojie's raw jade material was cut out first, and everyone was surprised when they heard that it contained jade. To their surprise, there was really jade inside.
Afterwards, everyone turned to look at Gu Ning to see her reaction, especially Zhao Rong. He wanted to see Gu Ning's anxiety and worry. However, he was disappointed, because Gu Ning looked extremely calm.
Kang Shaojie wasn't too excited, because it wasn't the final result yet. In addition, Gu Ning stayed calm so he believed that she might be better than him. Or she didn't care about the result at all.
Kang Shaojie was confident about his opinion of Gu Ning, and felt she was confident rather than arrogant.