Art is everywhere, it just needs someone to say "Look, there it is!" the act of choosing creates it (although it may not be any good as 'art').
Art has no message other than it's own existance. Any percieved message is based on interpretation of the producer and/or the experiencer.
Oh, and "all possible images with 256 colours, 320 x 240" can't possibly be "created ramdomly" it is the mathmatical expresion of all possible values of the 76800 points in the picture - all 19660800 of them.