There was some controversy that they ripped off the designs of many of these rooms without giving the designers credit:
http://www.mirror.co.uk/news/world-news/designer-sues-airbnb...
http://www.mirror.co.uk/news/world-news/designer-sues-airbnb...
I don't know how copyright works for interior design, but if it were a book she wrote, and then someone else rewrote without permission, there'd clearly be room for claiming a violation.