She's just charming, isn't she? Shows what one person can do with a bunch of sequencers. Lots of stuff is laid down before and then she does some keyboard work and sings. With adroit use of technology, she literally doesn't need another musician. But these days, she is becoming a big star (some of her videos have 10 million views) and she has an actual stage show with two female dancers. Here she is doing a tune called "Circumambient" live with dancers.
Here is a full video production of a song called Genesis:
Those costumes and imagery almost take us into Lady Gaga territory. Now what else does this remind me of? Well, some of the basic approach resembles EDM (electronic dance music) à la Deadmau5:
There's a guy up there with a bunch of pre-sequenced stuff and he hits the space bar and away we go. I talked about Deadmau5 in this post. But I hear other stuff in Grimes. There is a bit of an echo of the Eurhythmics with Annie Lennox:
And maybe there is even a bit of something a bit further afield. Don't all those layered voices remind you of Henryk Górecki?
She herself refers to a "medieval" influence so perhaps she and Górecki simply share some influences. I have to say that this kind of music is not really my thing, but I found myself listening to songs all the way through, which I usually don't do with pop music of any kind, so there might be something here.