With an item like a pram or a car, you can take it to a nearby area such as a park or carpark so that people can see it without coming into your home.

With a sofa/couch, I would want to see it if I were spending serious money on it if the description wasn't up to much. I know when DH has sold small things some people ask for a photo of a particular aspect or for more details, which are usually supplied promptly.