As this was the rockets first test flights, they would not put on a hundred million dollar satellite. During test flights, in the past NASA used a giant dead weight, so this is not an usual thing to do. Obviously the car is, but the weight is part of the testing.
I think its a funny publicity stunt. That picture is photoshopped by the way. The other camera is facing directly at the dummy from the front.
Also, the car is being sent into deep space. It is not in orbit around the earth. That would be a terrible idea, you are right about that!