Screen technologies increasingly permeate the experience of public space in Hong Kong. Large media walls have occupied the façades of many buildings, rendering a cityscape with dynamic information visible as a new urban skin. This article is a case study on Artificial Landscape, a site-specific media art project located on Asia Pacific’s largest LED outdoor screen. The case sets an example of how a public screen can serve as a mediating agent. It provides an opportunity for artists to provoke absent ideas in the public space and explore subversive potential, including critical reflection on issues surrounding surveillance, consumerism and rapid urban growth. The case also exemplifies how a public screen can mediate the public to experience an alternative context through artistic intervention, where negotiations of perceptions and subjectivities are made possible. This article provides insights into a public screen’s mode of spectatorship, quality of public space and curatorial strategies in an urban context. This is achieved by illustrating how various artworks extend the notion of publicness and remediate the mutually constitutive relationship among the built environment, media technologies, artists, public and everyday encounters.