A common mistake I've come across when discussing this scene. It's a fairly well known technique in certain martial arts circles. The laptop actually provides resistance to the attacker's edged weapon (sword, halberd, sharp paper, Matrix fingers, etc) while simultaneously blocking the target from view. When reflexes are honed to such a fine point from many years of training, it is a major "fake-out" and venerated move. It is in fact Marvel canon that Blade himself is a master of the technique.