I think that jane worked out two theories of who is red john. The first one is to show red john his work of finding him and the second one is in his head.

The first one, the episode when homeland security broke into jane' place he was very happy. Then he showed the cd to teresa he had those pictures, he had hem in order and where came those pictures. He is messing with red john's head and no one seems to notice.

The second one is in his mind. For all we know he might already know who is red john. Notice when he showed the cd he was facing away, and kind of smiling.