I found it to be quite disturbing because it was just so jarring. The rest of the episode was slow, even the kid getting hit crossing the street had a gradual build to it. The scene reminded me a lot of the ultraviolence found in Nicolas Winding Refn's films, ie violence that is so abrupt & unabashedly graphic that he proudly compares it to pornography.
It almost seems, much in the way that a different band closes each ep, that Lynch is playing us a violence mixtape: the Bad Cooper stuff was incredibly No Country for Old Men -esque, the two kids on the couch was very Nightmare on Elm Street, the crime scene was Seven-y, kid getting hit was classic Peaks melodrama, etc.