This article articulates screenness to comprehend the agency of screens in the postmedia condition. Being a common element in different kinds of media, screens contribute towards medial collaboration and relationality in postmedia where they do much more than display. Screenness, understood in Karen Barad’s agential realist framework, is performative and contingent upon the relations of the postmedia assemblage, considered here as an arrangement of technical, medial and human components brought together by the transferability and exchange across different media. The unstable, ever-changing relations in postmedia assemblages help in understanding the various operations of screens in image-making, display and dissemination practices. If screens can be understood in and through practices in which they emerge then their agency too is not static but changes as per the relations screens are in. To demonstrate the performative agency of screens – screenness – I will discuss intra-actions that can be gleaned via the activity of navigation using Google Maps application on a smartphone.