I'm mellow I'm just in your face mellow
That pot thing was in reference to the 420 at the end of the guy's name. 4:20 is international pot smoking time so people put at the end of their names to hint at their coolness.
Not that there is anything wrong with it but I don't think the motive behind this guy's madness is really constructive. I think he is just trying to illustrate to us how dumb he perceives Christians to be.