Archery, Arrows & Arrow Flight — There is a critical distance at about 5 to 8 metres. If the arrow hits fetching end "up", the nocking point needs to be lowered, and if it hits tail end down, the nocking point needs to be raised.
In archery, it is important to keep your shoulders in line. In picture A, the individual would have a difficult time aiming because they are using their muscles to hold the bow. I realize that you use muscles to hold the bow, but in picture B, the individual is using the bones in their arm to hold the pressure of the bow, allowing for a steadier aim.