Answer

Sylas didn't respond to Lauren's words. He only calmly analyzed that she was a person capable of speaking such words but didn't take them very seriously. In fact, he only began to calmly observe her. 

Lauren's gaze flickered. There was something about Sylas' gaze that made her feel particularly uncomfortable. He was staring at her like he was analyzing any other thing; she might as well have not been a person at all. 

She could see through his thoughts. He, in one part, wanted to keep an eye on a dangerous enemy, but he also wanted to observe why she was so confident. 

When she got here and saw the state of their progress, Lauren was quite confident that even if Sylas observed her actions, he wouldn't gain anything from it. That was why she had spoken so boldly. Though… that wasn't entirely just to take jabs at Sylas either.