This might be down to different interpretations - my sense is that she is being figurative, yours is that she's being literal. For instance I described Song for the Setting Sun Part 1 & 2 by Daniel Bachman as follows in a review: "the first part is a small group of friends passing around a bottle as they sit close by the fire they have lit on the riverbank - when the tempo changes half way through to mark the setting of the sun, you can see the embers flying away into the night sky. The second part is like a slow dance tune, couples coming together, drifting apart and melting into the darkness." Clearly none of these things are literally correct - it's a two part fingerstyle acoustic guitar instrumental.

I listened to a track off the new Jenny Hval album - I'd describe it as influenced by Bjork and Hissing of Summer Lawns era Joni Mitchell. As the mainstream media and music industry labelled Joni a folk singer, that might be the point of reference. And unless the reviewer is deeply involved in the folk scene and aware of its nuances and precisions, there's no reason why she wouldn't call it folk - to her no doubt it is. As far as I can see, it's only a subset of folk enthusiasts and academics who are particularly taxed about such things, and this is probably not her intended audience.