I think the picture is likely deceiving. First, look at where the nuts are relative to the hands. The top nut is at the last knuckle of the middle finger and the bottom is around the base of the thumb. I'm almost 6' 1" tall, and I don't have small hands. On me, that measures 5". So, if those were my hands, the nuts would each be about 1.6" tall presuming they are touching. The front left nut is about 3 fingers wide. That measures bout 2 1/4" on my hand. Next, look at the fingernails. I would guess those are the hands of a woman and likely smaller than my hands.
Big nuts, yes, but not as large as they look in the picture. I'm guessing the camera lens has a lot to do with the optics. In every batch of Dunstan chestnuts I buy, there are always a few unusually large ones.
Thanks
Jack