If I am de-cyphering that photograph correctly, Howard's lower finger is just floating on the string, not really holding any weight once it gets to full draw.
I've done that my whole life, placing about 97 percent of the bow weight on two fingers once I am at full draw. I start my draw with 33.3 percent on each finger, but at full draw, my lower finger is there only for looks.
Until just now, I thought I was the only one who basically shoots with two fingers.
Nate, any insights? Is it just the angle of the photograph? Am I crazy? (Don't answer that last question---you may cause others to laugh out loud,and this is a SERIOUS forum).