I was first introduced to Jung's ideas via two books by the the Canadian psychologist Graham Jackson- The Secret Lore of Gardening
and The Living Room Mysteries: Patterns of Male Intimacy
. Graham places the inner archetypal dynamic between men along two central color axes: green and yellow; blue and red. (Example: a green and yellow relationship might be between a gardener and a philospher.) I've found his ideas to be provocative stuff.
Here's some sources on the Shadow.
The shadow is an unconscious complex that is defined as the diametrical opposite of the conscious self, the ego. The shadow represents everything that the conscious person does not wish to acknowledge within themselves. For instance, someone who identifies as being kind has a shadow that is harsh or unkind. Conversely, an individual who is brutal has a kind shadow. The shadow of persons who are convinced that they are ugly appears to be beautiful.
The shadow is not necessarily good or bad. It simply counterbalances some of the one-sided dimensions of our personality. Jung emphasized the importance of being aware of shadow material and incorporating it into conscious awareness, lest one project these attributes onto others.
The shadow in dreams is often represented by dark figures of the same gender as the dreamer, such as gangsters or prostitutes or beggars or liars.
If you imagine someone who is brave enough to withdraw all his projections, then you get an individual who is conscious of a pretty thick shadow. Such a man has saddled himself with new problems and conflicts. He has become a serious problem to himself, as he is now unable to say that they do this or that, they are wrong, and they must be fought against. He lives in the "House of the Gathering." Such a man knows that whatever is wrong in the world is in himself, and if he only learns to deal with his own shadow he has done something real for the world. He has succeeded in shouldering at least an infinitesimal part of the gigantic, unsolved social problems of our day.
In light of the above, one might say that, for gay men, porn is the place where one's unacknowledged desires can be faced for what they are. Or course, this is true for everyone, but gay men, because of the social stigma associated with homosexuality, can have a tough time dealing with things.
My feeling is that, if one's projections aren't faced they end up eating us alive, much like a pool of water which has no in or outlet. The stagnant pool becomes toxic to itself and give off a poisonous green glow.