PHASE 1: VISUAL DECONSTRUCTION - **Fabric Physics:** The source garment appears to be a medium-weight cotton or linen blend with a matte finish. It exhibits low specularity (no shine) and moderate stiffness, meaning it tends to fold sharply rather than drape like a liquid. It should diffuse light evenly without metallic highlights. - **Key Features:** The intricate floral block print (reds and greens on mustard yellow) must remain undistorted. Crucial structural details include the pointed collar, the central button placket, the chest pocket stitching lines, and the cuffed/hemmed mid-length sleeves. PHASE 2: FIT & DRAPE SIMULATION - **Body Mapping:** The target pose features a distinct asymmetry with the right hand placed on the hip. The simulation must introduce tension folds radiating from the right hip upward toward the armpit. On the left side (holding the bag), the garment should hang relatively straight due to gravity but drape naturally over the upper arm curvature. The boxy cut of the source shirt means it should not cling tightly to the waist but hover slightly off the torso. - **Occlusion Handling:** CRITICAL: The black shoulder bag strap traversing the user's torso diagonally must be segmented and layered *over* the new yellow shirt. Additionally, the user's long hair falling over both shoulders and the upper chest creates complex occlusion; the hair strands must be masked out and composited on top of the floral pattern. The right wrist/hand resting on the hip must mask the shirt hem. PHASE 3: ENVIRONMENT & LIGHTING - **Light Match:** The target environment utilizes top-down, slightly harsh artificial indoor lighting (warm cast). We must calculate ambient occlusion where the hair meets the shoulders and where the arm rests against the torso to create realistic contact shadows. The source garment's flat, soft lighting must be replaced with a gradient that darkens towards the bottom and sides to match the room's vignette. - **Color Calibration:** The source garment's vibrant mustard yellow must be desaturated slightly and warmed to match the tungsten/indoor lighting temperature of the user's photo. The white balance of the fabric needs to shift away from the cool daylight of the source image to blend with the beige/cream tiled background tones. PHASE 4: IDENTITY PROTECTION - **Facial Lock:** Absolute pixel preservation required for the user's face, neck area above the collarbone, and hairline. The jawline definition must remain sharp and unaltered. - **Body Integrity:** Strict prohibition on warping the user's underlying anatomical mesh. The user's arm circumference, waist width, and posture must remain identical. The lower body (jeans) and the plastic bag in the left hand are outside the generation zone and must be frozen.