Bingo. The illusion of size isn't there.
this is silly...
you are seeing a pic of a dude standing by himself...
he is a real 6'2 which arnold never was lol!

if you were to put arnold in his prime next to this dude , arnold would get killed... ( and i am an arnold fan...)
everything is just bigger, denser, and more conditioned... remember muscle = heavier then fat mass....
1cm3 of blubber will be of a greater volume then the same quantity of muscle...
his legs are more developed, and there is a LOT of weight in legs.
his back as well, far more developed..... also a lot of weight goes there....
you guys are looking at arms, and chest... small bodyparts.....
but comparing bb from different era is very stupid.... Arnold was king in his era.... this dude is a nobody in his.....