This paper describes an algorithm enabling a human supervisor to convey task-level information to a robot by using stylus gestures to circle one or more objects within the field of view of a robot-mounted camera. These gestures serve to segment the unknown objects from the environment. Our method's main novelty lies in its use of appearance-based object “reacquisition” to reconstitute the supervisory gestures (and corresponding segmentation hints), even for robot viewpoints spatially and/or temporally distant from the viewpoint underlying the original gesture. Reacquisition is particularly challenging within relatively dynamic and unstructured environments.