From my understanding - which is probably limited and biased - Shadow can be revealed in many different ways. Anyone, not just same sex, can ignite parts of ourselves that we ignore/hate/need to integrate. The animus/anima states that we all carry aspects of the opposite sex with in us. Yin/yang, light/dark, male/female, ect.
In terms of the projection - I think it centers around the idea that we keep things hidden from ourselves. As I have gotten older, slowly things have been revealed that I never realized in the past. If you would would have told me XYZ about myself 5 years ago, I wouldn't have really understood or felt the words, or maybe even agreed to them cognitively. But truth does eventually get revealed!

So, in my understanding, when Jung says that our shadow is that which we deny, projections are like an outlet for those. And we place blame on the other (projection) b/c we can't own this part of ourselves. And that is how it gets revealed. I think it's unconscious - not a failure of knowing one's self.

I offer up a bit of caution when exploring this topic. Jung's concepts are so interesting. But be weary of the head trip that can go along with this. Boundaries, holding others accountable for their actions, not over-taking responsibility, validation, ect - are important as well. Not every feeling is a projection, and I think that is where it gets confusing for me.