It is definitely not the bare light bulbs that I lived with in some rooms for far too long until I found the right lamp shades!
It is not cheap paper or plastic shades - you can get both paper and plastic lamp shades which look a million dollars but they probably cost a little more than a few dollars and they have a designer look to them. (See finding the right lamp shades)
It is not fake antique lamps of any description unless they match the quality of the original. Just compare the quality of a genuine Tiffany lamp with the cheapest reproduction and you'll see what I mean.
I suppose you can say that
- luxury lighting enhances your room - it has the right design to go with your other decorating choices and looks like a part of the design
- it adds appropriate light to create the right atmosphere and level of light for the function of the room
- it has a touch of quality about it - it looks expensive even if it isn't
