I think that the different L/E shape on that NASA thingy is a product of the kinked planform, dihedral and the angle of the view!
Hmmm.....
One day while doodling at the NASA design office....
"Hey Bob, check this one out."
"Idiot, you drew the leading edges differently!"
"She's good, on one will notice."
Did the French firm make any other racers? This is a racer I presume?