Upload a supplier's moulding-length photo and a photo to frame, enter the real sizes, and it composites a rough preview — tiled moulding round the edge, sized to scale. Not meant to look perfect, just to give an idea.
Rough scale mockup only — corners are mitred (45° join) but grain direction isn't matched across the join, and the photo is centre-cropped to fill the frame. Good enough to gauge whether the idea's worth building properly, not a final render.