Retouching covers the small faults a camera cannot avoid: dust on a dark garment, lint and pet hair, creases from folding, a loose thread, a reflection in a watch glass, a colour that came out too warm. Cutting the product from its background and matching colour across a set are usually part of the same job, so that every image of a collection looks as if it came from one shoot.
The line that matters to a buyer runs between correcting the picture and changing the product. Removing a crease from transport is cleaning; removing pilling, slimming a seam, brightening a faded print or hiding a scuff on a used item misrepresents what will arrive. Many marketplaces state that edits must not change how the item looks, and some do not accept edited photos of second-hand goods at all.
Heavy retouching shows. Over-smoothed fabric loses its texture and looks like plastic in zoom, a cut-out with a hard or haloed edge looks pasted on, and colour pushed for impact no longer matches the real dye. A sound routine is to retouch from the original file, compare the result side by side with the product in daylight, and check edges and fabric at full size before upload.