This art depicts the 12 possible permutations of the holy name of God י-ה-ו-ה.
Each month of the year corresponds spiritually to one of these permutations.
The Hebrew months correspond to the cycle of the moon. When the moon appears at sunset as its smallest crescent, it is the first day of the new Hebrew month. When the moon is full, it is the middle day of the month. When the moon reappears again as a tiny crescent, it is the first day of the next month. Each month corresponds to a particular spiritual energy and aspect of consciousness. The spiritual energies of the 12 months of the year correspond to the 12 permutations of the divine name.
A Kabbalah meditation is to meditate each month on the corresponding permutation of the divine name. The month of Nisan is associated with the normal order of the name depicted at the top center of the picture. The permutations continue in the order of the months counterclockwise. On the final month of Adar, the meditation is on all 12 of the permutations together.
These permutations are hidden in the first and last letters of verses in the Torah. The vowel notations with the holy names are the vowels of the letters in the corresponding verses from the Torah. We do not pronounce these holy names. They are used in meditation.
This cycle of spiritual progression also happens every day as the 12 permutations also correspond to the 12 hours of the day and 12 hours of the night.
Kabbalah describes how this cycle of spiritual progression is a microcosm of our spiritual development to our ultimate state of unconditional love and divine union.