People inherently share spaces with other people. Congenitally, interactive technologies and ubiquitous environments shape our opportunities for enacting social relations. Proxemics and Spatial Sharing have been suggested as foundations for our understanding of the socio-spatial aspects of computing. By tandeming these theoretical perspectives in a set of cases in the office domain, we develop a contribution comprised of 3 key sensitizing concepts: Proxemics Malleability, Proxemics Threshold and Proxemics Gravity articulating socio-spatial qualities at the interplay between interactive systems, spaces, interior elements and co-located people. The sensitizing concepts qualify interaction designers in considering proxemics consequences of technology design; they serve both as analytic lenses in understanding the socio-spatial qualities of a context and as generative instruments in a design process. The proposed sensitizing concepts and the theoretical work of the paper contribute to enhanced Socio-spatial literacy in HCI.