This is a really interesting question
Without wishing to be a pedant, Jung had two shadows; the archetype or the personal. I'm guessing this is the Personal as that would make sense in this context
An archetypal Shadow is the collective idea of 'bad' or 'evil' such as the Devil (and if you see Nietzsche here you're spot on).
The Personal Shadow is the dregs of our unconscious like a tar filter on a cigarette. It is primordial. We can look at the (Jungian) personality like the sea, at the bottom are those weird creatures with huge eyes that never see the light of day. Only rarely do we catch a glimpse of them and there are many of which we are not aware. When we do examine some of them they can be traced back to the time of dinosaurs like the Frilly Shark and some of them look terrifying like the Viperfish or Fangtooth fish.
So the Shadow is all the bad stuff, all that gunk we try to deny which Freud explained in 'projection' where we project onto others what we most dislike in ourselves. A collective shadow was cast on the Jews who were dehumanised by the Nazis and came to represent everything hated and feared in society. (It seems to be done to a lesser extent in the West with Islam and vice versa).
The more we divide and splinter ourselves from our shadow side, the more it is denied and repressed, the more destructive it becomes. The Shadow is natural and part of being human and it is crucial to Jungian analysis to accept and assimilate it into the main personality nexus. Good things to come from the Shadow are creativity and spirituality but in order to release this we must become responsible for our shadow sides.
It's all fascinating stuff
How I would initially interpret the reversed Hanged Man is under the auspices of what I most dislike about others or that part of my shadow I project onto others. I'm not sure what this means to you but what do you most despise? Then I would write it down and apply it to the Hanged Man. A negative aspect of the Hanged Man may be as a traitor as the way he is depicted with he one foot bound (pittura infamante) and it is in searching for those aspects within yourself that you will find your key to its meaning. This may be difficult because these aspects (complexes) are forcibly repressed, pushed down deep in the primordial sea of the unconscious with their sharp fangs and weird survival mechanisms. Coming to terms with your Shadow may involve some Shadow Boxing, allowing it to express itself at times and facing it down at others.