To express either a picture's contained information or it's abstract description from within the picture itself, the picture must be altered from the original state. Thus a picture cannot be truly self-descriptive.
A void picture containing a number n of black pixels would contain n bits of information "black pixel", or zero bits of "white pixel". This cannot be expressed from within the picture, as it would mean either adding or changing a minimum of at least one bit of information. From within the picture's context, both the arbitrarily coded expressions "This picture contains n black pixels" and "This picture contains 0 white pixels" yield either false statements, or alter the picture, respectively.0xFFFFFF.html
In other words: A truly self-descriptive picture would necessarily contain a description of it's own already, rendering any self-descriptiveness pointless.