This looks vaguely like xpm, but monochrome and vectorized. xpm is an image format that is also valid C code, so you can #include "image.xpm" in your C source code.
Also kinda like XBM, a file format that was happily supported in the browser - and you could create the images in JavaScript! http://www.mrspeaker.net/2005/03/27/xmb-images/ - unfortunately, IE was first to discontinue it in 2006 (http://www.mrspeaker.net/2006/09/04/the-end-of-xbm/), and Firefox followed. My guess is it was too obvious of a security hole vector for an image format that no one actually used ;)
XPM isn't monochrome either, though. I always thought XPM was an elegant hack, since I could just #include my icons into the C source for my Xt or Motif applications. I don't miss the rest of Xt and Motif, particularly the pseudo-object-oriented C style code, or the twenty kilograms of O'Reilly books containing the documentation!
https://en.wikipedia.org/wiki/X_PixMap#Comparison_with_other...