Haylie was amusing Fred. She couldn't help but find her a little cute in the way she persisted, so she decided to play with the girl a little. "Fine," she replied as she stared into the other girl's eyes, "But first." Fred's eyes flashed yellow for a moment as she began to create an illusion for Haylie. It appeared as though Fred reached under the table to grab a mirror, "Why are you naked?" she asked in the illusion while she held up a mirror for the girl to see the herself with no clothes on. The moment Haylie would look down to see, obviously the illusion would be broken and she would find Fred laughing.
She didn't do things with her illusions just to amuse for too many people, and really probably only just the two (Lex and Cait); therefore, the fact she did it to Haylie was possibly her way of telling the other girl she was alright.