Symbolism, Imagery, Allegory
When Grant, Sattler, and Malcolm first set foot on the island and get to see the infrastructure, they immediately take note of the form of the buildings. They're not built in the manner of zoo or amusement park structures; they built as "military" fortifications (2.9.25). Moats and electric fences add to the fortifications. What gives?
As they proceed through the park, the guests notice that even more fortifications have been put in place. Thick metal fences clash with their surroundings. It's pretty clear that these additions were placed in response to some incident, instead of proactively from the start.
The whole of Jurassic Park, the buildings included, screams DANGER. Everything has been created without thought for the consequences (the only consequence anyone cares about is the $$$), and now the park employees are trying to contain those consequences retroactively. As we know, it ain't gonna work.