Requirements gold plating is not the same as developer gold plating. Requirements gold plating is done by the project manager, the client asks for something, and the project manager responds, how about we also do this to complement your request, and we'll do it for free! Requirements gold plating is about suggesting to the client more than he had asked for, and committing to the client for those add-ons (for free).
Developer gold plating is done at the developer level, and the client is not aware of it. Developers, in order to shine or for their own personal satisfaction, tend to add "bells and whistles" to the project that are not in the requirements. Clients may not appreciate developer gold plating.
Both requirements gold plating and developer gold plating are bad, but requirements gold plating are the sign of a truly bad project manager.