One thought- Notice the ring around the aperture is split, maybe the peep itself has a ring around it and is also offset in that ring, allowing both peep and outer ring to be rotated and each giving eccentric adjustment. That would get complicated quick for my little pea brain.
Yeah.. I've been thinking the same thing. If there were two "rings" that could be adjusted, one that moved the sight up and down, and the other left or right...
There are marked lines on both the front and rear rings, so that may be how it works.
