She was shocked to see him there. She took out her phone to see if she had accidentally mistaken Finn for Levi when texting him. But no. When she opened her texts, she saw Finn's name on it. She was confused and realised that she had mixed up their phone numbers.
Levi saw her and the expression of surprise and discomfort she had. She also looked like she was expecting someone else. She didn't know that he had seen her, so he got up and as he walked towards her; he gestured to the waiter to quietly leave. He took out his phone and called her, standing behind her.