Based on the complex dynamic system approach, this research aimed to study the variability of the typical configurations of interactions between the adults' participation and the engagement of a child with autism spectrum disorder (ASD) in two activities proposed in a French preschool. The classroom sessions were filmed once a month for 8 months and focused on two activities (free play and adult-led activities). The results of this preliminary exploration revealed that the typical interactions developed differently over time. Indeed, during activities that are adult led, observation behaviors with a passive participation of the adult intensified. Moreover, active engagement behaviors, without and with adult participation, increased meaningfully during free play.