One possible theme could be 'protection'. The glass case is there to protect whatever is inside it, and this could extend to themes about protecting one's heart, ideas, or secrets in a more metaphorical sense.
The theme could also be 'isolation'. Just as the item in the glass case is separated from the outside world, there could be a character or idea in the story that is isolated. This could be about a person who is socially isolated or a group that is cut off from the rest of society, and the glass case serves as a symbol of that isolation.
Another theme might be 'curiosity'. Since the glass case is mentioned, it likely draws the characters' (and the readers') curiosity. They want to know what's in it, which can lead to themes about the human desire to explore and discover the unknown.
It could be a story where the glass case plays a crucial role. Maybe it contains something precious, like a valuable artifact or a mysterious object that drives the plot forward.
The theme might also be about perception. Since we are seeing 'in a glass darkly', it could suggest that our understanding is limited and the story may be about how characters struggle with their misperceptions or try to break through to a clearer view of things.
The main idea could be centered around the glass case as a symbol of protection or isolation. Maybe the characters inside or around the glass case are either shielded from something or cut off from the rest of the world.
I haven't read 'the glass case' specifically. But generally, when analyzing a short story, one can look at elements like the characters. Are they well - developed? What are their motives? Then there's the plot. Does it have a clear beginning, middle, and end? And the setting, which can greatly influence the mood of the story.
The main theme could be self - discovery. In the story, the looking glass might symbolize a tool for the character to look inward and understand themselves better.
The main theme is probably kindness and the power of a small act of giving. The glass of milk could symbolize the basic human compassion that can have a big impact on someone in need.
The main theme could be the pursuit of the impossible. The character in the story tries to climb the glass mountain which is extremely difficult and dangerous, representing the human aspiration towards seemingly unachievable goals.
Another theme might be reflection. A shard of glass can be reflective, and in the story, it could symbolize self - reflection for the characters. They might look at the shard and see themselves or their situation more clearly. For instance, a character who has been living in denial might finally face their true self when looking at the shard of glass.
The main theme could be isolation. The character in the story might be isolated from society or from meaningful human connections, which causes them pain.
It could be a simple story of a child being denied a glass of water as a punishment and the impact it has on them. Or perhaps it's a sci-fi tale where the water in the glass has special powers that change the course of events.