The Angel and the Dark Man vs The Reformer
In the Reformer the goat represents the personality who has transgressed into the unconscious and encounters the shadow. The ego is then "caught between hammer and anvil, both the accuser and the accused” (C.G. Jung, Memories, Dreams, Reflections) The goat is equally innocent and guilty. Her desire to leave the farm and return to Nature even if it means facing the wolf is motivated by an unconscious yearning towards wholeness. By leaving the farm she loses her innocence and the challenge now is to avoid wanting that innocence back and endure the feelings of guilt and shame during the integration of the shadow.
Symbolically, the white of the goat with the pink moon halo are analogous to the red and white colors of the conscious personality emerging from the swamp. The pink moon refers to Nick Drake’s song Pink Moon (and none of you stand so tall, Pink Moon’s gonna get you all) and could symbolize the red helmet/spirit that came from meeting the shadow. The tree is shaped like a hand with pointed index finger, the hand of justice pointed at the ego and symbol of the guilt surrounding the meeting of the shadow.
The thistle, with its prickliness, is seen in popular belief as a gift of the Devil. Mythically, it doesn't grow in the Garden of Eden but appears as a curse after the Fall (The Book of Symbols, Taschen, p. 166).
The Fall from Eden perhaps then happens when we fail to recognize the opposites and thus create a shadow.
In the Tarot the card that would most closely express the conflict of meeting the shadow and confronting the opposites would be The Tower, where the tower represents the Devil’s kingdom and the Devil losing its crown.
A possible source of inspiration for the imagery may be “the Harrowing of Hell, in which Jesus forces open the fiery tower gate of Hell to free the virtuous dead from Limbo.” The limbo would be the state the goat/ego is in, and the tree would be the tower (some decks also have the card showing a tree instead of a tower and called Lightning). Jesus then is analogous to the angel in the Splendor Solis and the Pink Moon halo in my drawing, the transcendent or Feminine Principle who rescues the alchemical process by providing a garment that can cloth both conscious personality and shadow with the help of feminine compassion and self-acceptance.
Note: the quotes in italic are from the book by J.L. Henderson and D.N. Sherwood, Transformation of the Psyche: The Symbolic Alchemy of the Splendor Solis