上半保留真实，下半重新涂色

Turn each uploaded photo into its own high-end design poster, built on a [composition ratio: 3:4] vertical split where the top and bottom halves sit at a strict 1:1 — each claiming half the frame. Keep the top half as the original photo. For the bottom half, first identify the core theme most worth remembering from that photo, then rebuild it as a [illustration style: pastel hand-drawn graffiti material collage illustration with retro paper texture]. Pull [color count: 2–4 kinds] of the most vivid, friendly colors straight from the upper photo to re-tune the palette below.

把每张上传的照片都做成一张独立的高级设计海报，采用[composition ratio: 3:4]竖版分割，上下两部分严格1:1对半分，各占画面一半。上半部分保留原图。下半部分先提炼出原图里最值得记住的核心主题，再把它重建为一幅[illustration style: pastel hand-drawn graffiti material collage illustration with retro paper texture]。色彩上直接从上半原图里抽取[color count: 2–4 kinds]种最鲜活、最友好的颜色，重新调配到下方画面里。