In the near future, robots will support human to perform tasks in many domains (industrial, domestic, educational and health tasks). Such robot behaviors need to take into account the social interaction between robot and human. In this context, we focus on the expressiveness of a moving head for an assistive robot for the elderly. We designed a new moving head for the Kompaï companion robot. On one hand, this new head improves its perception capabilities. On the other hand, we expect to jointly increase its social skills and thus its acceptability. This new head is composed of a tablet to animate a virtual face according to 4 facial expressions and a mechanical neck with 4 degrees of freedom to enhance the robot's expression. Before improving face expressions and adding more complex head movements, it is essential to evaluate the combination of simple head movements with virtual face expressions. A study was held jointly with physicians (psychologists, ergonomists) at the Broca Hospital in Paris to assess the impact to combine head movements with virtual face expressions, and the global acceptability of the Kompaï head by the elderly.