Classic of Embryonic Breathing - The embryo
Type of spiritual experience
This is entirely symbolic and is describing what happens after 'union' - moksha
Shen = Higher spirit
Ignore the comments in brackets unless they provide some extra missing verb, they are not helpful
The Xin, very approximately is the Subconscious mind shown on the diagram with its perceptions and emotions. The Yi is the Conscious mind, with Reason, Memory, Desires, the Personality and Learning activites [for all definitions of these see the Model of the Mind]. The Shen/Higher spirit makes up this divisioning into three of the mind.