I understand the words glimpse and insight, but what is the meaning of the whole idiom a glimpse of insight?
- Anybody can ask a question
- Anybody can answer
- The best answers are voted up and rise to the top
Glimpse here means a short experience of something, while insight means an understanding of something.
means the film helps us understand their lives better by a little bit, since the film is only a few hours long but their lives are years long. Perhaps we should not see it as an idiom but rather a concatenation of the two meanings.
This is not a standard idiom. The author is either a non-native speaker or a native speaker using a slightly unusual phrase for deliberate (e.g. poetic) effect.
If you understand both words you'll probably be able to make sense of the author's (I assume) intended meaning: an insight perceived briefly as if glimpsed.
Glimpse is almost always used in a physical sense of seeing briefly. Insight is always mental understanding. Therefore, I'd say glimpse and insight don't go very well together in a phrase. In Jasper Loy's example the sentence
would probably be better off with just 'glimpse' (or just 'insight').
While we are at it, 'flash of insight' is more commonly used to describe sudden, unexpected understanding