Previous studies have shown that students learn better from an online lesson when a gesturing pedagogical agent is added (Mayer & DaPra, 2012; Wang, Li, Mayer, & Liu, 2018). The goal of this study is to pinpoint which aspect of a gesturing pedagogical agent causes an improvement in learning from an online lesson. College students learned about neural transmission in an online multimedia lesson that included a pedagogical agent who displayed specific pointing gestures (i.e., pointing to the specific component in the diagram being mentioned in the narration), general pointing gestures (i.e., pointing in the general direction of the diagram), nonpointing gestures (moving hands as beats, moving an arm up or down, or crossing two hands), or no gestures. An analysis of students' eye movements during learning showed that students in the specific-pointing group paid more attention to task-related elements than did students in the other groups (as indicated by fixation time and fixation count on the target area of interest). Students in the specific-pointing group also performed better than the other groups on retention and transfer tests administered immediately after the lesson and after a 1-week delay. The results show that an active ingredient in effective pedagogical agents is the use of specific pointing gestures. This work helps clarify the embodiment principle and image principle by isolating specific pointing (or deictic gestures) as a key feature that makes gesturing effective in multimedia lessons. Educational Impact and Implications Statement: When students learn from multimedia lessons with onscreen pedagogical agents, does the type of gesturing by the agent affect student learning? In this study, students learned better and paid more attention to relevant material on the screen when the onscreen agent used specific pointing gestures during instruction rather than general pointing gestures, nonpointing gestures, or no gestures. Specifically pointing to relevant parts of the onscreen graphic while talking guides the learner's attention and leads to better learning.