This study presents the Observatory of Childhood Culture -- OBECI -- a professional development community in the making. It describes its origins, constitution and functioning. It reports some of its achievements at the level of promoting participatory pedagogies for children's learning and professionals' development. To make the transformation processes visible (which are the core of a praxeological knowledge development) this study uses the methodology of praxeological studies. This paper focus on the reflexive discussions developed around the relationship between adults and children in order to reveal emerging knowledge from the training processes deployed in the Observatory of Childhood Culture -- OBECI.