These two GIF images are programs "painted" in the programming language Piet. If you run them with the Piet interpreter, they will both print "secunet". (The "codel size" is 8 for the left one and 16 for the right one. These values are needed to properly run the Piet interpreter.)
Another Piet program printing "secunet" is here.
(More about Piet.)
Download the source.