Written within the framework of the Master's degree in Communication and Digital Technology, at Celsa and in collaboration with the Ecole des Mines d'Alès, this thesis deals with one of the many phenomena that have appeared on the net, both ephemeral and revealing of new social practices: the dédipix. The analysis of this phenomenon will be an opportunity to shed light on the new social uses linked to the web, within the framework of an ever-renewed self-exposure.