Scholarship has largely been conducted on publics’ ‘offline’ public art encounters, while public art practice has become increasingly integrated with virtual dimensions. This article aims to fill this gap by focusing on digitally mediated public art engagement. A case study on the travelling Rubber Duck exhibition (2012–present) interrogates how this artwork is appropriated and narrated through digitally networked spaces (mainly social media, forums and news platforms) after its repeated on-site installations. This article argues for the need to expand on ‘virtual relationality’: the communication, (re-)negotiation and (re-)siting of public art’s roles and meanings through (mainly text- and image-based) social mediations within hybrid, online-offline contexts. Public art encounters are examined along fluid cybergeographical understandings of its social and spatial publicness, temporalities and uses, which deconstruct binaries including material/digital space, permanence/ephemerality and human/non-human.