++1, I think the minutes hand being in a standard position is key - similar to any other regulator watch tbh (patek, GO, etc.)
It's made in Antwerp, my hometown The case is completely filled with oil I thought so you could read it well under water
It's for that visual effect mostly I thought - similar to some smart phones, it gives the effect that the dial is right on the edge of the glass. Sinn do have a piece that has an oil filled dial too I think