Vote Brigading is the practice of mobilizing a campaign within an online community to promote or undermine a targeted page, user or belief en masse through the user-voting system. On Reddit, brigading is often employed as a silencing tactic by those who wish to undermine the presence of competing political agendas or opinions.
It's from a meme, in which in that panel, he usually says "Jesse, what the fuck are you talking about?"
Thanks!