Sefirot and Letters
This picture is of the kabbalistic Tree of Life. The names of the Sefirot are written around the circles. Although Daat (Knowledge or Consciousness) is not usually included as one of the Ten Sefirot, this picture includes Daat (the white circle).
The lines that connect the circles (Sefirot) have the Twenty-Hebrew Letters written on them according to their order in Sefer Yetzirah. The Three Mothers (ש Shin, א Aleph and ם Final Mem) can be seen on the top three Horizontal lines. The Seven Double Letters can be seen on the Vertical Lines that connect the circles. The seventh Double Letter (ת Tav) is also on the lowest Horizontal line, because Tav the last letter of the Hebrew alphabet is related to Earth and is thus Brown. The vertical lines that extend above and below the circles are marked with the Mother Letters because Shin (Fire), Mem (Water) and Aleph (Air) also represent the three Vertical Columns of the Tree of Life.
The Twelve Simple Letters are upon the twelve Diagonal lines that connect the circles. They also extend beyond the circles to connect the Tree to a larger whole.