The original box heads were Swedes, and others such as Albanians or Russians are merely Johnny-come-latelys to the group.
I drive a boxy Volvo because I am a box head.
2) An insult, used to mock people with the condition described in definition 1).
Gary: LOL way to trip walking up the stairs Rus, you Box Head.
Russell: Stop making fun of me, I hate you so much.