  There is growing interest in the language developed by agents interacting in
emergent-communication settings. Earlier studies have focused on the agents'
symbol usage, rather than on their representation of visual input. In this
paper, we consider the referential games of Lazaridou et al. (2017) and
investigate the representations the agents develop during their evolving
interaction. We find that the agents establish successful communication by
inducing visual representations that almost perfectly align with each other,
but, surprisingly, do not capture the conceptual properties of the objects
depicted in the input images. We conclude that, if we are interested in
developing language-like communication systems, we must pay more attention to
the visual semantics agents associate to the symbols they use.
