This chapter focuses on how to support teachers in designing conditions for developing children’s imagination during late infancy and toddlerhood. The aim was to understand how imaginary play situations in a Conceptual PlayWorld could help teachers bring into group care settings more possibilities for the development of children’s imagination. To achieve this aim, an educational experiment was set up in a middle-class suburb in southeast Melbourne with two educators who worked with 13 infants-toddlers aged between 0.1 and 2.2 years. In following Hedegaard’s conceptions of motives and demands as key analytical concepts, we sought to understand educators’ professional practices in relation to the developmental conditions created for children within the activity settings of the childcare centre. The new educational practices that resulted from the intervention of a Conceptual PlayWorld showed: (1) collective explorations and emotional imaginings being supported by educators within the different activity settings; (2) educators bringing mature forms of imaginary play into the activity settings which infant-toddlers co-experienced; and (3) how imaginary play begins to form in the collective actions and emotionally amplified dramatisations created by the teachers. Under the conditions of an intervention, the study found educator responsiveness in introducing play content and role-development, where the infants co-experienced being a play partner and began to build an understanding of self through acting ‘as if’ a character in imaginary play. The new enabling practices of emotional imagining that was co-experienced transitioned infants and toddlers in their role-relations to early forms of “as if” role-play. This chapter adds to theoretical understandings of how educators can support the earliest forms of the development of imagination in group care settings where emotional imagining is core.