I don't LOVE the rug. but I think the green curtain, built-in shelves filled with books and the (presumably) sliding ladder are wonderful. Its missing a fire place, lots of cozy blankets and an oriental rug!
bookshelfporn: DIY Ladder Bookshelves To get this look, all you need are two ladders and some wood planks. Paint the ladders and the wood if you want, then slide the wood planks through the ladders so they are resting on the ladder steps.