Back in the days when this book was written, thick pile carpets were seen as luxurious. Wall to wall carpets were also a thing as they needed to be fitted, rather than a large rug. In today's world we might consider wooden flooring as being luxurious.
Sure, I remember wall-to-wall carpets. But I don't understand the comment about "Whole tribes of pygmies are wondering why the light stays on at night". What's that all about? *shrug*
The pile on the carpets is so tall, that tribes of pygmies could live in it and think it's a forest - but the lights (being lamps inside a room, rather than the sun) stay on at night (if someone's working late, I guess).
Possibly just a vague reference to The Carpet People?