She couldn't help but genuinely smile at his... honesty? Humility? Something, but it was refreshing.
Also refreshing was the fact that he didn't seem to mind showing her how much he seemed to like her - compliments, making it a special evening, wanting to impress but also be true to himself... It was refreshing compared to the mixed signals she was (maybe?) getting from elsewhere. Well, she'd kind of told herself they might be mixed signals, though the more practical side of her said that was ridiculous.
"I appreciate it, the effort," she said with a shy smile and a slight blush. "It's refreshing," she didn't explain that one.