I might be wrong, and I don't want to question the possibility that someone from a non-technical domain can contribute to technical domains (in particular because neural networks and style transfer are basically high school mathematics; and since this happened before [1]), but it seems to me that the paper in question does not contain much technical innovation, but it is rather a demonstration of how existing techniques can be used in practice [2].
This article gives some evidence: [1], quoting:
> researchers were a bit perplexed when actress and director Kristen Stewart [2] appeared as an author on a machine learning paper.
[1] https://techcrunch.com/2017/01/19/kristen-stewart-co-authore...
[2] https://en.wikipedia.org/wiki/Kristen_Stewart