Went through my pictures and as expected I've got few of this detail. Not easy to see and the "flap" in the outer edge of the bracket blocks the view of the rubber bumper at the base in most of the pictures
I'm guessing that you have the bumpers with the horizontal lines at the base rather than the lines across mid way or towards the bottom end.
On the few where I could make out the orientation that all appeared to have been inserted with the "lines" in the bumper on/towards the passenger side of the car
Hope this helps is some way