The ability to model other agents can be of great value in multi-agent sequential decision making problems and has become more accessible due to the introduction of deep learning into reinforcement learning. In this study, the aim is to investigate the usefulness of modelling other agents using variational autoencoder based models in partially observable settings. Previous studies that model other agents using (variational) autoencoders have shown promising results. In these studies, a single protagonist agent learns representations of other agents to then use them as additional components of its observation space which is, as such, augmented with those representations. It is, however, not always entirely clear what is being modelled and what would be the best feature of the other agent to represent. Moreover, in these works, a comparison between the used variational autoencoder based models and a baseline classifier trained to solve the same classification task is missing. This study investigates which features can best be used for the augmentation of the observations of deep reinforcement learning agents and if these features can be represented by variational autoencoder based models. Subsequently, it compares these models with a baseline classifier that solves the same classification problem to find out which model yields the best results when used for augmenting observations. Overall, the results suggest that it is beneficial to augment the observations of deep reinforcement learning agents with features related to other agents learned in a pre-training phase. Another interesting result is that the baseline classifier achieves similar or better performance compared to the variational autoencoder based model. Further research needs to be conducted to confirm the soundness of these findings.