Because of the movie’s presence there are facilities that are completely unnecessary — from its ridiculously oversized loading dock, to its large assortment of industrial water chillers — but it lends a sense of the fantastical to the place.
This detail very much speaks to the special relationship that existed between the Die Hard production and the in-construction skyscraper.
With some exceptions, such as the Nakatomi Corporation Christmas Party, all of the scenes set in the building were shot in and around it.
One could make a strong argument that it’s the largest practical prop in cinematic history, as, within reason, the film was able to utilize the entirety of it.