• Nuances are the small differences between things. For example royal blue and ocean blue.
• Subtletites are things that sometime go unknowticed but add to the detail of something.

As nouns the difference between nuance and subtletyis that nuance is a minor distinction while subtlety is (uncountable) the quality or fact of being subtle.

This topic is about capturing subtle and naunce aspects in a bigger picture. Perhaps a small detail in a landscape that tells the story.