What we're seeing here is the early stages of what's known as 'pan hands' - the spaces between the knuckles on each finger swell in size, forming oval shaped 'pans' which aid in wife beating later in life. With all four fingers extended the 'pans' create a long, flat and more importantly, hard (yet tender) surface which maximises pain when impacting the face/eye area while reducing chances of bruising. I may have just made that up.