Teaching via lecture video has become the defacto standard for remote education, but videos make it difficult to interpret instructors' nonverbal referencing to the content. This is problematic, as nonverbal cues are essential for students to follow and understand a lecture. As remedy, we explored different proxies representing instructors' pointing gestures and gaze to provide students a point of reference in a lecture video: no proxy, gesture proxy, gaze proxy, alternating proxy, and concurrent proxies. In an online study with 100 students, we evaluated the proxies' effects on mental effort, cognitive load, learning performance, and user experience. Our results show that the proxies had no significant effect on learning-directed aspects and that the gesture and alternating proxy achieved the highest pragmatic quality. Furthermore, we found that alternating between proxies is a promising approach providing students with information about instructors' pointing and gaze position in a lecture video.