Kane is a French Mastiff who looks like a hulking brute, but he's really just a sweetheart in disguise. Still, as with any good dog, he's a loyal protector of his humans and is always ready to stare down a potential threat.
In this clip, he comes across a mirror - and he doesn't like what he sees. Standing in front of him is another giant mastiff, matching his fierce glare perfectly! When he growls, the other dog growls. It seems like neither is backing down. Kane even barks to try to intimidate this strange intruder, but the dog barks right back at him!
Kane's clearly ready to stand his ground... even if it's against his own reflection. At least it'd be an opponent he could finally consider worthy of the challenge, and a handsome one at that! Thankfully, his human steps in and calms him down before things get too crazy.
H/T: mydogcane1's channel