In line with educational issues involved in emergent literacy practices in preschool, in particularthose concerning comprehension processes, this paper focuses on picture-based narrative comprehensionduring an interactive reading session of a wordless picture book, involving a group of children aged threeand their teacher. Children are asked to make inferences about the meaning and outcome of the story, aprocedure which gradually elicits their responses on how events link together, thus enhancing their capacityto use prior and implicit knowledge to build the story meaning. Moreover, this study highlights theimportance of interaction for developing comprehension.Data collected was analysed following didactic microgenesis, an analytical approach showing that knowledgebuilt during interaction depends on the joint construction of a zone of common meaning by whichteacher and children try to adjust to each other. In order to help the process of merging different meaningsof the story built online, a text written by researchers, following the narrative structure of the story, wasread by the teacher after the picture-based reading. This led us to examine through interactional analysiswhich semiotic cues were used during recall on the following day, as an additional measure of knowledgeconstruction.