搜了下 "why macbook smells good"，得到如下：

https://www.quora.com/Why-does-Apple-packaging-have-a-distinct-smell

Of course, Apple won’t reveal the original combination of fragrances that goes on to create that smell. However, very recently, a Melbourne based artistic group “Greatest Hits” requested the famous scent marketing company “Air Aroma” to replicate this very fragrance for their art exhibition and to a great extent, they have succeeded. They are calling it "Eau de Mac Unboxing". However, it is not for sale!

For the record, that elusive smell is a combination of ozone, burnt plastic (polystyrene) used for wrapping, the smell of cardboard and quality paper and above all the massive piece of aluminum product. Some believe that the particular style of packaging and the process involved back in China factories are responsible for this odd but nice smell.

I personally find it is deliberately introduced in Apple products to induce the feeling into its consumer’s mind that they have bought a beautiful and essential product “all must and glory”!

翻译：
当然，Apple 不会透露产生这种气味的原始香料组合。然而，最近，墨尔本的一个艺术团体“Greatest Hits”要求著名的香水营销公司“Air Aroma”为他们的艺术展览复制这款香水，并在很大程度上获得了成功。他们称之为“Eau de Mac Unboxing”。但是，它是非卖品！ 根据记录，这种难以捉摸的气味混合了臭氧、用于包装的烧焦塑料（聚苯乙烯）、纸板和优质纸张的气味，尤其是大块铝制品的气味。有些人认为，这种奇怪但好闻的气味是由中国工厂的特殊包装风格和工艺造成的。 我个人发现它是故意在 Apple 产品中引入的，目的是让消费者产生一种感觉，即他们购买了一款美丽而必不可少的产品，“all must and glory”！