Taken out of context
During processing, there may be circumstances where a totally black pixel (either all 1s or all 0s, depending on how its coded), can have a bit added or subtracted as part of contrast stretch or some other enhancement meant for the rest of the image. If the brightness level "wraps around" it can go from all black to all white by just the addidition of a single bit to each byte.
Also, the similarity of this image to the cartoon provided as an example by Marcia below is uncanny. And another thing, what's with the grid superimposed on the image?