This one's pretty obvious. After all, the protagonist herself has two names: Miyax and Julie. We might think of those two names as two sides to her character: Miyax, the authentic Eskimo, and Julie, the girl who struggles to fit her Eskimo heritage into her Americanized surroundings.
Okay that's nice and all, but what are we supposed to do with that information? Good question. Here's what we're thinking: our heroine's two names help us understand the identity crisis she's facing. When she moves to town and lives a more modern life, she's Julie. But when she lives in seal camp and on the tundra, she's Miyax, through and through. It's telling that at the end of the book, when she concludes, "That the hour of the wolf and the Eskimo is over" (3.263), and she "[points] her boots toward Kapugen" (3.264), the narrator calls her Julie. Each name stands in for a different side of our heroine, and these sides are duking it out for control over Miyax/Julie's identity. Such drama!
The names of the wolves, too, help us understand their characters a bit more. Amaroq, we're told, is simply the Eskimo word for wolf. And it's telling that Miyax names the brave young wolf pup Kapu, after her father, whom she admires so much. Jello is named for the way he wiggles when he's cowing to Amaroq.
When it comes to the wolves, we (and Miyax) have only their actions by which to judge them. Because they don't speak (big surprise, there), Miyax must figure out the language of their behavior in order to understand them and talk to them. In fact, much of the first section of the book consists of the wolves' actions, and Miyax's rather impressive translation of them. Let's take a look at a key example:
The wolf arched his neck and narrowed his eyes. He pressed his ears forward. She waved. He drew back his lops and showed his teeth. […] When she was flat on her stomach, Amaroq flattened his ears and wagged his tail once. Then he tossed his head and looked away. (1.23)
It's only a few pages later when Miyax figures it out:
He had told her to lie down. She had even understood and obeyed him. He had talked to her not with his voice, but with his ears, eyes, and lips; and he had even commended her with a wag of his tail. (1.32)
From Amaroq's actions, it's clear that he's the wolf in charge. He's the one that tells everyone else, including Miyax, what to do. He tells Miyax to lie down. And lo and behold, she does, without even realizing at first that she was following orders. Miyax, like the other wolves, knows that Amaroq's the boss because he behaves like the boss; his actions communicate his position in the pack.
Just to drive this home, let's take a peek at another wolf, and see how his actions help us understand his character. Throughout her time with the wolves, Miyax has tense run-ins with Jello, who seems to not quite fit in with the rest of the pack. Then, as she watches the wolves trot away, she sees Jello, running separate from the rest, "head down, low to the ground – in the manner of the lone wolf" (1.256).
Just from this one action alone – running apart from the pack, with his head down – Miyax knows that something is deeply wrong with Jello's relationship with the other wolves. She knows that Jello is a loner and a bit of a loser, if we may say so. He's just not fitting in. And of course, many pages later, her worry comes true when Jello is killed by the pack for his bad, lone wolf behavior.
By props in Julie of the Wolves, we mean possessions, and this particular tool is really only relevant to Miyax's dad, Kapugen. In his house at seal camp, he's got all kinds of traditional Eskimo goods—harpoons, knives, walrus tusks, a kayak, and a camp stove (2.6). But when Miyax arrives at his house in Kangik, she realizes that he now has all kinds of fancy possessions, like a radio-phonograph, a telephone, an electric stove, and even an airplane (3.258).
Big deal. So the man's got a stove. But to Miyax, this is beyond a big deal. It's a Big Fat Deal. It shows just how much her father has changed from the man she knew in childhood, and that change is totally essential for understanding just who he is. Kapugen is not the man we (or Miyax, for that matter) thought he was. He's gone modern, and his values have changed. All it takes is the narrator naming a few of his new possessions for this point to be driven home.