The purpose of this study was to investigate supervisory interventions during counseling supervision process and their impact on the supervisee. Sessions of a volunteer supervision dyad were recorded, and materials of supervisee-perceived impact were collected by using Interpersonal Process Recall (IPR). Thirteen events were taken into account and analyzed. All events were intensively analyzed by adopting the framework of Discrimination Model. Results of the study showed that the supervisory intervention with the focus on process and the role of teacher was most common of all, and the focus on personalization changed with supervision stages. Second, most of the impact on the supervisee was positive. The supervisee’s feelings often underwent some kind of transition during an event. Seven categories of global impact of events were concluded. Lastly, supervisee-perceived impact changed with the supervisor’s interventions, apparently with the supervisor’s role assumed. Implications for practice and research are discussed.