Here's the new me.
Since I feel LLD (leg length discrepancy), I asked the OS to show me how they measure it on the x-ray. They draw a line parallel to the pelvis by having the line just touch the openings indicated by the arrows.
Then they see where this line intersects the femur on each leg - right on that "little knobby piece" (sorry I don't know the name for it) on the inside of each femur. As you can see, mine is almost identical, just slightly higher on the right leg (left side of photo), which means from that point down is slightly longer on the right leg .... 1 or 2 mm at the most. That's quite small, but also quite noticeable at first to the patient. It's getting better and they tell me in 4-6 months my muscles will have become accustomed to it as my new set point.