The crowd screams for Lorde like she's a pop star. They roar at the start of every song, from her big singles to her album cuts to her Replacements cover. They cheer when she moves to their side of the stage or when she points out someone in the crowd.
They are not bothered by the fact that she doesn't move like a pop star or dress like a pop star or have the elaborate stage setup of a pop star. They don't even mind that her songs aren't overproduced messes or that she sings about subjects that upper-class artists ignore.
These are good things, because pop music needs someone like Lorde. Yeah, party-rocking and twerking may pack the arenas, but a sold-out crowd singing back more than just the hits makes a good argument that people care about what she has to say, too.