Mediatized communication is increasingly communication by visuals. Visualization challenges Communication Studies as an empirical diagnosis as well as a theoretical task. The author of this dissertation starts from a perspective that draws on mediatization theory and theory of action. In the theoretical part, he outlines the concept of visual mediatization research focusing on figurations of visibility. Besides, he discusses the linguistic bias of action-oriented communication theory and explores junctions for its aesthetical broadening. In the empirical part, he presents a study on the change of private picture practices by taking the example of young people's use of visuals in social network sites. The research highlights the importance of visuals as means of articulation, mediated presence and participation, and reflects on the theatrical and attention-economical conditions produced by new media environments.