The role of the representations that are developed in creativity sessions is often overlooked as a potential factor, which can influence the progression and the results of those sessions. Through the qualitative analysis of a case, observed in an open innovation center called Ideas Lab, we will explain the use, the nature and the functions of representations developed during a creativity session. We aim at articulating Duval’s representational cognitive functions and the mode of attribution of meaning, polysemic versus monosemic, in creativity sessions as specific situations. In addition to the classical cognitive functions of Duval’s framework, we propose a new cognitive function of representation that we call the modulation of ambiguity specific to the creative process. The representation allows the adjustment of the ambiguity level to give way to a variety of interpretations. This potential of the modulation of polysemy supports the idea generation activity by introducing or preserving a variety of interpretations, and prepares the idea evaluation phase by reducing polysemy and supporting the construction of a common understanding