Jon had freaked out when he realized how Karyn had changed reality ... at first. But now that he was really thinking about it, he was intrigued, and decided to change reality in the same way that Karyn had a day earlier.
So when he made his wish and came back to his room, everything was as it was before Karyn ended her wish moments ago. But the thing was, Karyn believed that this was how the world was supposed to be, and Jon knew that it wasn't. Of course, he remembered all the memories from that reality, since Karyn had wished him to, so he was able to fit in better than Karyn was able to when she changed reality like this the previous day.
Karyn looked up at Jon and asked "Did you already wish for something?" Just like earlier when she arrived at Jon's house, she was wearing a T-shirt and baggy jeans.
Jon nodded.
Karyn looked around at Jon's pinkish bedroom, the posters of girl bands and romantic movies, Jon's vanity, and then to Jon himself, who was dressed in a yellow halter top, denim miniskirt and 2-inch heels. It's what he was wearing a moment ago before he left the room. "I can't tell what's different. Everything seems the same."
"Well, I'm sure you'll get it," Jon said, his lipsticked lips forming a smile. Though, after what he learned the last two times they've done this, the chances of Karyn finding out weren't very good. He just wanted her to think she had a chance to figure it out.