Yes, that’s the infamous WO hand sign.
I think it was you (fillippone) who coined it?
But I seem to recall it should be performed with the right hand if showing the palm, so that the three fingers and the looped index+thumb read WO. Or with the left hand if showing the hand's back? The last word on this belongs to the coiner. I mean, the person who coined the sign. No reference to, you know, the coin.
I can confirm I made with my left hand, so that it was more easily to make it similar to the letters “WO”.
Someone found some satanic referee on that, but the sole deity I worship is Satoshi.