Create a 15-second ultra-realistic vertical smartphone vlog featuring the same clearly adult Korean female idol. Make this a completely different concept from the previous fan-meeting vlog: she unexpectedly discovers a small good-luck surprise from her staff just before going on stage. The footage must feel like genuine smartphone footage recorded by the idol herself, with natural handheld movement, realistic front-camera perspective, subtle autofocus shifts, imperfect framing, authentic skin texture, natural facial expressions, realistic hands and fingers, and believable backstage ambience. Avoid polished commercial-video aesthetics. 0–4 sec: She walks down a backstage hallway filming herself. She suddenly notices something off-camera, turns toward it with a surprised smile, and says softly, "Wait… what?" 4–8 sec: She enters a small preparation room and discovers a tiny decorated cake and a handwritten "Good Luck!" note waiting for her. She laughs genuinely, picks up the note, and briefly shows it to the camera. 8–11 sec: She looks back at the camera with a touched smile, takes a tiny bite of the cake, then laughs because a little frosting gets near her lip. A staff member jokingly calls her name from outside the room. 11–15 sec: She quickly walks toward the stage entrance while filming. The camera catches colorful stage lights and faint audience sounds ahead. She turns the phone toward herself, takes a deep breath, makes a small finger heart, smiles confidently, and says, "Okay, let's go!" She turns the camera forward and walks onto the stage, ending naturally. Realism requirements: continuous character identity, consistent outfit and hairstyle, physically correct anatomy, no extra fingers, no duplicated objects, no warped hands, no sudden outfit changes, no floating props, no unnatural facial movement, no excessive camera shake, no artificial transitions. Keep the performance spontaneous, warm, and believable, like an actual Korean idol's personal backstage vlog. Output: 15 seconds, 9:16 vertical, realistic smartphone video, natural audio ambience, authentic handheld selfie footage.