Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Controlled
You might be hard-pressed to find a more controlled writer than Hemingway. The word "control" generally implies that there is something that needs to be controlled, right? There's a conflict between restraint and rebellion present in this story, but Hemingway only suggests it. The husband and wife are at odds and discontent with one another, but they don't talk about it. Instead, the tension lies in their lack of real interaction. There's an unhappiness that they are studiously avoiding, but trapped as they are in their room on this rainy day, as each other's only company and as the only Americans at the hotel, the awkwardness becomes pretty concentrated. Hemingway's sentences, both in the dialogue and the descriptions, are terse. It's so clipped that you know that there's something being excluded. Thanks for leaving us hanging, Ernest.