A diorama is a diorama is a diorama. Or is it? It is easy to think that we ‘know’ dioramas, or in other words, that the phenomenon of the diorama is completely unambiguous across cultures. In the present chapter, we illustrate the multitude of conditions and constraints that influence the design and the subsequent interpretation of dioramas. Specifically, we compare two dioramas with respect to the processes by which they come into being, and the processes by which they are interpreted by visitors, across two contexts: The Zoology Museum of the University of São Paulo in Brazil, and the Zoology Museum of the University of Copenhagen in Denmark. We use a comparative approach because placing the conditions and constraints of two different cases in critical and dialectical relation to one another across cultures enables us to observe not only what these conditions and constraints are, but also, what they are not (Kreps 2006). Ultimately, we make the point that as museum practitioners and researchers, we must always question the constraints and conditions that surround the production of dioramas as well as their reception by museum visitors, to fully understand their educational role in contemporary natural history museums.