Answer: This is a guess, but possibly to match the scenery/imagery of the scene
Explanation: since the author is pointing out many tropical details, such as coconut white, mango yellow, or children jumping into waves, the author is driving more interest into there piece by saying cactus fence instead of just fence. Again, just a guess.
I would say it’s the first or second. I’m leaning towards the second. Mostly because I don’t know key ideas from this story.
