The adoption of conversational agents is growing at a rapid pace. Agents however, are not optimised to simulate key social aspects of situated human conversational environments. Humans are intellectually biased towards social activity when facing more anthropomorphic agents or when presented with subtle social cues. In this work, we explore the effects of simulating anthropomorphism and social eye-gaze in three conversational agents. We tested whether subjects’ visual attention would be similar to agents in different forms of embodiment and social eye-gaze. In a within-subject situated interaction study (N=30), we asked subjects to engage in task-oriented dialogue with a smart speaker and two variations of a social robot. We observed shifting of interactive behaviour by human users, as shown in differences in behavioural and objective measures. With a trade-off in task performance, social facilitation is higher with more anthropomorphic social agents when performing the same task.