Much of the everyday lives of young people happens on social media, mainly those image-centric platforms, like Instagram. Participation in these platforms has increased practices of meaning-making associated with vernacular literacies. Digital production on Instagram articulates traditions from vernacular writing and photography and is characterized by the mass-circulation, hybridized genres and texts, and the centrality of the image. In this article, I examine the role of image as a precursor of meaning and writing on social media, and the functions and patterns of production present in the practices of 2 Chilean young people. The functions of documentary and testimony; self-expression and identity; sociality, audience, and participation are interwoven with each other and with the patterns that organize the knowledge associated with the production. Based on this discussion, I offer some suggestions in order to broaden the understanding and teaching of writing and digital literacies.