Chris' explanation, Photoshop fakery, is very possibly the correct explanation, but, assuming it is not an intentional fake, Argos' comment that it could be some sort of reflections is also a very good possibility.
There is a phenomena called "lens flare". One of its many forms occurs when light from a very bright area in the image (eg, the sun and sky appearing through the vertical slit of the trees) bounces between the individual lens elements that make up a modern camera lens, and a distorted and out of focus secondary image of the bright area appears elsewhere in the image. If you want an example of one of the oddest forms of lens flare that I have ever seen, take a look at this image:
http://static.photo.net/attachments/bboard/00W/00WMhC-240595684.jpg . It took us over 10 pages of discussion to get to the bottom of this,
http://photo.net/digital-camera-forum/00WLVN?start=110, but we finally nailed it down.
BTW, a purple color for the secondary image is quite uncommon with this type of lens flare. It happens because the anti-reflection coatings applied to camera lenses generally work well, but sometimes permit odd colors like purple to bounce around.
There is a huge history of lens flare and other optical phenomena getting honest people riled up and attributing the resulting ghost image as an apparition of some kind. If you want to have some fun, just go to Google images and enter the following search:{orbs in photos meaning}.
Bottom line: With what I know about this image, I can't distinguish between an intentional Photoshop hoax and an extremely common fault of lenses, "lens flare", but I can most definitely assure you that it is not a ghost.
Tom M