The latest update clairifies a lot.
It sounds like the initial surgery was to stop blood loss, repair blood flow and nerves to the lower half of her leg to use for reconstruction.
The second surgery was to clean up and remove dead tissue.
On Tuesday they will amputate the leg above the knee, take the lower half tissue they saved from their work on the first surgery and use it to reconstruct her thigh so that she will be able to keep the leg and be able to use a prosthetic.
Given the extent of the damage this is pretty amazing work and explains why they did the surgery to restore blood flow to the lower leg. Pretty brilliant.
They state her entire quadricep was taken by the shark so I believe the photo may very well be from this incident.
A post was made that it couldn't be her because the person in the photo is overweight. I don't see this at all, rather what the photo illustrates is how tight you should synch down a tourniquet. And naturally without any tendons and muscle holding anything together the flesh is going to look inflated.