It's supposed to be a picture. The whole thing is that the exposure is screwing with what color people see the dress.
I just felt like seeing what people saw it as, considering it exploded all over the internet in a few hours.
Its not screwing with what color people see the dress as, the over exposure changed the color of the dress from the real life blue and black, to white and gold for the image, the same as using a paint tool in a photo editing program would, or switching to image negative colors would change the colors used.
The dress is black and blue, but the colors in the image are white and gold. The difference in which one people decide to use is as simple as this: