Super Smash Brothers - Bowser Jr. is Ambidextrous

"U wot, little fgt?! Ill ave u no, Im the fookin son of Bowzr. U want dis sord up ur fookin arsehol? Thot so, m8. Oi! Any othr fgts wanna git dek'd?!"

I don't think this about mirroring. I mean after all Jr's model is actually rotating not just flipping. I think this is a weapon quirk to make sure players can easily tell what weapon they and their opponents are carrying.