This ambigram is simply my initials, "S A B", for Seth Alan Bareiss. (I'm the webmaster of www.TESSELLATIONS.org)
Freemasons, draftsmen, engineers, bricklayers, architects, and carpenters will recognize the compass and square, which are usually represented with a "G" in the kite-shaped space at the center. I joined the Freemasons decades ago, and found them a fine bunch of fellows, though one of the central beliefs-- belief in a deity-- is outside my own belief system. They are often maligned by outsiders as some sort of arch criminal organization. Nothing, really, could be further from the truth. It's an open society with some secrets, and is generally aimed at building society in a positive way-- metaphorical masonry. As a person with access to Freemason literature, I was quite stunned and a bit proud to learn how much of the language and symbolism of Freemasonry is in, for example, the symbols and documents of the U.S. Government.
Anyway, the compass and square very much belong in a website dedicated to M. C. Escher style art, and in a symbol I use to sign my work. I use mine every day; I assume Escher did as well.