Mirror therapy (MT), which is used in the existing stroke rehabilitation environment, has significant limitations for use with severe stroke patients. Since mirrors only reflect symmetrical movement, allowing a patient to observe precise asymmetrical movement is impossible. This study proposes a new MT system by developing a pyramid hologram technology that uses delayed motion to create realistic images. Significant differences, observed via electroencephalogram, were shown in all motor cortex channels immediately after the event in the delayed condition when compared to before the event (C3: p < 0.001; Cz: p < 0.001, C4: p < 0.001). The illusion of asymmetrical movement using the proposed system can be applied to severe stroke patients to increase the positive outcome of rehabilitation.