Just over Kurt and Sue's heads is a complete view of Half Dome's shoulder.  If you look closely, you can see a few specs on the center runway below.  Those are humans.

The junction between the shoulder and Half Dome itself forms a classic saddle point, upward slant front and back, drop-off right and left.   It resembles a natural bridge of sorts.  It would be more thrilling to cross when wet from rain.  Fortunately, I have not had that experience.  And besides, the signs say "lightening strikes Half Dome every month of every year.  If the hair on the back of your neck stands up, do not climb the cables."... er, lightening rod.