HuH wasn't like their previews songs - it wasn't autotuned, it had a solid melody, that tiny little bit of class, and a heck of a lot of attitude. To a certain extent I think they started out with all attitude and no finesse, so the minute they got it I jumped on the song.
But one more, very important, point to establish is that these girls can actually pull the song off, live or recorded. They can sing it, they can perform it, they can sell it - very few, non-big 3, girl groups can actually do that.
The song has a very generic structure with a very repetitive chorus, but what I like about it is that they're actually singing throughout the song, and it's clear to listeners when they're rapping and singing. Yes.