This article analyzes, from a theoretical perspective, the nature of the discourse generated, in computer mediated communication, by the interaction of two agents: adolescents and photoblogs. Photoblogs are a variety of Internet tools that allow young people, from thirteen to sixteen years old, approximately, to express themselves and to communicate with their peers through pictures. Symbols and representations visible in the interface allow for the study of multimodal speech generated in the display of contents. In this article we study two important concepts related to these contents: identity construction and socialization processes concerning subjects who participate in these media practices through multimodal discourse.