In video lectures, instructors naturally produce nonverbal behaviors, such as gestures, facial expressions, and gaze guidance. Instructors' pointing gestures can act as attentional cues, directing students' attention, while their positive facial expressions can act as social cues, eliciting students' positive social response. The current study examined whether an instructor's positive facial expressions weakened the benefits of the pointing gestures in video lectures. We designed an eye-tracking experiment, recruiting a total of 32 students. We found that when the instructor combined pointing gestures with positive facial expressions, students dwelled shorter on the slides and longer on the instructor, and showed lower learning performance. The results partially supported our hypotheses, suggesting that the effect of an instructor's pointing gestures on student learning could be influenced by the instructor's facial expressions in video lectures with slides. The findings offer valuable practical implications for enhancing the design of video lectures that feature an instructor alongside slides. Instructors should refrain from using attentional cues and positive-emotional social cues simultaneously to promote students' learning in video lectures.