El_Marsh posted...
^I believe it was to show that he's such an arrogant, know-it-all jackass that he
knew
the damn thing wasn't going to harm him because he was in control...which is Lex Luthor to the T
Yup, he has another moment just like this in the movie when Superman flips a table in front of his face and he just maintains an air of smug and calm superiority.
Gunn and Hoult did an incredible job of making this Lex so damn hateable that you just want to punch him in the face.