Carrot,

Isn't it paradoxical how in the first dream you knew that all DCs were your own projections, and yet in the second dream you had fears associated with a dreamt-up mirror? I'm curious: how would you explain such a discrepancy?

Lucid dreaming can bring out your fears, just as well as it can show your desires. Some people turn to sex in lucid dreams, other turn to superpowers, etc. My pet peeve has always been fear of the dark, and sure enough, most of my lucid dreams quite annoyingly started out in darkness. Lucid dreaming is walking through the realm of your mind, after all, so what you see is a reflection of emotions, desires, and fears inside of yourself.

That said, looking in the mirror is a normal thing to fear. You know that your reflection is likely to be different and you would experience a great shock seeing it. I never dared to do that myself, but whenever I tried to look at my body (during OBEs) the bed was empty, and I drew a conclusion that seeing it was too much for me too handle. There's something dreadful about seeing your body in a different way that you're used to. Your fear of the mirror must've been caused by similar feelings.