My interpretation is that the author wrote this article to find something about Kubrick that defines who he was. Kubrick is known to have demanded perfection,

My interpretation is that the author wrote this article to find something about Kubrick that defines who he was. Kubrick is known to have demanded perfection, jotting down tons and tons of notes and details. But the public only seems this side of Kubrick in the movies he makes. One can be a perfectionist about a trade, but carefree in other aspects of their life. But the boxes were the author's "Rosebud" in that even though no one outside of the estate would see/use these boxes, and by the looks of it would have rarely been opened, Kubrick still took the time to get boxes that were incredibly well-designed. So in essence, the boxes embodied Kubrick's true self, a perfectionists.