Detached, we say? Why yes, we do. This isn't a harsh judgment, it's just the way it is. Most of the time, the events of the story are simply related to the reader in a straightforward way, without any commentary. The narrator tells us what happens, and pretty much leaves it at that.
Even when events are fairly dramatic (we're thinking about the fight that breaks out between Zigzag and Zero, or Stanley's attempt to steal the truck), the narrator doesn't give us much information about the characters' emotional reactions. Instead, what we usually get is just a play-by-play of the events themselves. Here's an example from the Zero/Zigzag fight:
Zigzag made a gagging sound, as he desperately tried to pry Zero's arm off of him.
"You're going to kill him!" shouted Mr. Pendanski.
Zero kept squeezing.
Armpit charged into them, freeing Zigzag from Zero's choke hold. The three boys fell to the ground in different directions.
Mr. Pendanski fired his pistol into the air. (30.78-82)
Okay, what just happened? Well, one boy almost choked another to death, a third boy had to intervene and pry the two apart, and a counselor pulled out a gun and fired it. Pretty scary stuff, when you think about it. But we really don't hear about that fear or excitement or whatever else the characters must be feeling in the moment. Plus, we don't get any input from the narrator about what he thinks about the situation either.
The only clue we get, beyond the actual events themselves, is in that one word: "desperately." Not much to go on, overall. Because we have to figure it out for ourselves, sometimes our imaginations run wild. You might have had to break out the tissues a couple times while reading Holes, and when you think about it, those emotions come more from what wasn't said than from what was.
So why would the narrator approach the story this way? Hmm. Does the word "detached" make you think of anyone in the story? Say, Stanley? Like the narrator, Stanley never really tells anyone what he's feeling and always wants to stay on the sidelines of life (at least until the later part of the book). His way of reacting to conflict is usually to just lay low and try not to be noticed. The way Shmoop sees it, the narrator's tone of detachment mirrors the way Stanley feels through much of the book, reinforcing our impression of him as emotionally shut down and unresponsive.
It's not all detached all the time, though. The narrator often does give us clues that point us – be it subtly – toward an interpretation of the story's events. Here's where the "gently ironic" part comes in. Let's look at a passage near the beginning of the book:
If you take a bad boy and make him dig a hole every day in the hot sun, it will turn him into a good boy.
That was what some people thought. (2.3-4)
"That was what some people thought." Hmm…what are we supposed to make of that comment? Just who are these people the narrator is talking about? Does he agree with them? Why does he bring them up at all? It's a little hard to interpret. But one thing's for sure: if the narrator wanted us to take the bad-boy statement at face value, as something he believed without question, he probably would have left it as is. Instead, he adds a little comment, telling us that it's just what "some people" think. Automatically, we're clued into the fact that it's not what everybody thinks.
By putting certain statements together in particular ways, the narrator manages to slyly, gently suggest that there's more than one way of looking at things; that what one person asserts as truth may not necessarily be correct. And he does this all without ever actually telling us what he thinks. Impressive, right?