The grooves help the juice drain. If you could imagine pressing the bag against a flat surface, the juice would try to come out of the bag but have no where to go. The grooves give space for the juice to form a stream and pour out.
So I don’t think same or opposite the other side matters. The important thing is just that the juice isn’t pressing against a flat surface with no drainage.
@Namastecafeukiah.com Hello, Yes it doesn’t matter too much on the X-1, The press racks it is a habit for me to keep them so the top corner on each one, I try to keep it flush against the press, but shouldn’t be an issue to have it either way.