Update app.py

app.py

@@ -59,11 +59,15 @@ def run_pipeline(
         gc.collect()
         progress(1.0, desc="Done")
 
-        status = f"✅ Generated at exact 300 DPI — {STANDARDS[spec_choice].width_mm}×{STANDARDS[spec_choice].height_mm}mm"
+        status = f"✅ **{spec_choice}** — {STANDARDS[spec_choice].width_mm}×{STANDARDS[spec_choice].height_mm}mm @ 300 DPI ({photo.width}×{photo.height}px)"
         if sheet is not None:
             status += f" · tiled on {paper_key}"
 
-        return photo, sheet, status
+        # ImageSlider needs a (before, after) pair at the same canvas. We
+        # hand it (original upload, final result) — Gradio letterboxes/
+        # fits internally, so mismatched source aspect ratios display fine;
+        # it's a visual compare, not a pixel-aligned overlay.
+        return (image, photo), sheet, status
 
     except ValueError as e:
         # Expected, user-facing errors (no face detected, bad spec, photo
@@ -127,9 +131,12 @@ def build_interface() -> gr.Blocks:
                 generate_btn = gr.Button("Generate Photo", variant="primary", size="lg")
 
             with gr.Column(scale=1):
-                out_photo = gr.Image(type="pil", label="Passport Photo (300 DPI)")
-                out_sheet = gr.Image(type="pil", label="Print Sheet")
+                out_compare = gr.ImageSlider(
+                    label="Before / After — drag to compare",
+                    type="pil",
+                )
                 status_box = gr.Markdown()
+                out_sheet = gr.Image(type="pil", label="Print Sheet")
 
         # Update the color picker default whenever the standard changes,
         # so the user sees the correct expected background before they
@@ -147,7 +154,7 @@ def build_interface() -> gr.Blocks:
                 inp_image, spec_dropdown, bg_color, paper_dropdown,
                 zoom_slider, x_slider, y_slider,
             ],
-            outputs=[out_photo, out_sheet, status_box],
+            outputs=[out_compare, out_sheet, status_box],
         )
 
         reset_crop_btn.click(