Who Berne should be on the lookout for

Movement speed
The robot should establish interaction with “wanderers,” i.e. those who are walking slowly in a hesitant, crooked, or confused path.

Head movement / Gaze Behavior
The robot should focus on visitors who display erratic head and eye movement (i.e. moving head quickly left to right to survey the entire room as if they were new to the place).

Proximity
The robot should favor targets that are nearer to it.