I think your summary misses a main point of this article.

Entrepreneurs set up a very high-security art warehouse in Harlem (New York) with a main selling point that it enjoys a formal exemption from Federal import taxes on fine art. However, no such taxes exist in the U.S. The author believes that the tax exemption provides a kind of cachet for the warehouse even though there is no practical benefit, and that customers may not even realize that they don't get any financial benefit from storing artworks there.