I think they're pushing the "picture in space" as a sort of hook to gather public interest. Large scale public interest in their projects has the potential to bring in larger funding from entities that might otherwise not be interested.
Personally I think this is an excellent idea. The picture in space is a great little incentive to get people to take a closer look at the project.
Of course, there is the risk of failure and the bad PR that goes with it. That said, the list of endorsements they have is pretty impressive, and pushing the idea that a first grader could in theory direct the satellite to take a picture of his or her choice could give them a huge boost in interest.
