Any interaction is imbued with personality. We apply anthropomorphic qualities to objects in our everyday life whether that's calling malfunctioning machines names or applying gender characteristics to everyday objects. What the focus of this paper is researching whether these type of interactions can be created and studied.
It's interesting that they choose this area to focus on for their research since while common, I think most people just want a sofa to be a sofa. While users did start to form expectations of the sofa's, I feel that the novelty of these interactions would fade quickly over time.