The Philosopher and his Flask vs The Dreamer
The Philosopher on his journey investigating the Elements of nature can be compared to The Dreamer who follows his intuition and imagination in pursuit of other horizons. The two horses flying in the sky may symbolize the mercurial aspect of the Philosopher, the masculine and feminine, harmonized with music.
Note: the quote is from the book by J.L. Henderson and D.N. Sherwood, Transformation of the Psyche: The Symbolic Alchemy of the Splendor Solis