He saw that he was a girl, of course.
Or rather, he saw his breasts, and figured out he was a girl, but it was pretty much the same idea.
Linda, of course, was shocked upon meeting him, and he had to explain that, first of all, he really was Jon, and second, everyone within the wish range including his family thought he had always been a girl. He told her the whole story...
"... You mean Karyn is a blonde now?"
"Yeah, and everyone here remembers she was always that way."
"So why don't you change back?"
"Change back?"
"From what you said about that blue tree branch it's easy. Let me see that..."
Jon gave her the stone and she said "I wish that Jon was a girl because he has something that transforms people and he was a girl for a few minutes today, but he's male now."
A split second later, the breasts and the pink were gone. Everything was okay. Eventually, of course, they did wonder what the wish had done. Making his own wish, Jon said "I wish I knew what it is that I have that transforms people, and how to use it."
