It's an earlier model of this Galco holster:
M7X MATRIX: Galco Belt Holsters at Galco
So far as I know, there's no intentional extra retention to it. It just doesn't allow the gun out well at anything except an upward draw, and even that needs significant force. Interestingly, when it's not on the belt, it's a bit easier to draw if you know the holster. If anyone managed to get into my bedside safe without waking me, they'd likely take several seconds at least to free the gun from the holster. I can draw it from my belt or from the free holster because I've practiced and know how.
Essentially, I think it's a slightly defective holster, that happens to work for my purposes.