The horizontal hood was in the 1980’s and early 1990’s a lot more popular than the verticle one because it could be done with a Bead ring or ball closure ring and the bead could sit on the clitoris to give stimulation to the wearer.
However, this piercing only really works well if the woman has very small outer labia because if the outer labia are large it will twist the ring and become painful. Which is why the vertical hood became more popular.