It's try to bluff him back.

Hanzo recognizes the behavior. If it meant to kill him, it could have done. Instead it seems to be trying to scare him back out of its territory, the space it sees as belonging to it. Slowly, he eases the tension in his arm as it lowers by some degree, waiting to see what comes of it.

He's still a fool. But perhaps he won't pay for it with his life, if this continues on.