PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment is a structured, woven textile (likely wool blend or tweed) featuring a houndstooth pattern. It possesses high structural rigidity and low elasticity. Unlike the user's current knit/stretch fabric, this material will not cling to the waist. It has a matte finish with low specularity; light should diffuse across the surface rather than reflect sharply. - **Key Features:** The high-contrast black and white houndstooth pattern must undergo perspective warping without pixelation. Critical geometry includes the notched lapel collar, the deep V-neck opening revealing the black inner lining, the lack of sleeves (armhole structure), and the two horizontal welt pockets near the hip line. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** The vest is cut straight (boxier fit) compared to the user's current fitted peplum top. The simulation must ignore the "flare" of the current peplum and instead drape the vest vertically from the shoulders, likely creating a gap between the garment and the user's natural waist. Since the target has sleeves and the source is sleeveless, the simulation must generate realistic skin texture for the user's upper arms or imply a layer underneath if generation is restricted. - **Occlusion Handling:** The user's left hand (holding the phone) and the phone itself are critical foreground elements. The vest must be rendered on a layer *behind* the hand and phone. The necklace area and the user's visible hair falling behind the neck must be segmented and layered appropriately over the collar of the vest. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The user image features soft, diffuse, slightly warm (tungsten) indoor lighting coming from above and slightly to the left (reflected in the mirror). The generated vest must accept shadows cast by the user's phone-holding arm. The rendering must match the slight ISO noise/grain present in the mirror selfie to avoid looking "pasted on." - **Color Calibration:** The source image is cool-toned (studio lighting). The white sections of the houndstooth pattern must be color-graded towards the warm, yellowish hues of the user's room to integrate seamlessly. The deep blacks of the vest must be lifted slightly to match the dynamic range of the user's photo (black point compensation). PHASE 4: IDENTITY PROTECTION - **Facial Lock:** The user's visible forehead, right eye, right cheek, and ear must remain frozen. The phone covering the center face acts as a hard mask and must not be altered or textured over. - **Body Integrity:** The user's shoulder width, arm volume, and neck length must remain strictly unaltered. While the *clothing* silhouette will change (from hourglass peplum to straight vest), the underlying biological mesh of the user must not be slimmed or warped.