To write a good scene, ask yourself some questions:
- Who are the characters in this world? What are they doing? Why?
- Are they all doing the same thing?
- Who will I focus on?
- What physical elements are in the scene? How might characters interact with them?
- How would these elements feel or smell?
- What history might be behind some of these elements?
- What could be the significance of any of these elements?
You don't have to have all the answers before you start writing. Let your mind wander through the image, until you come up with a starting point, then start writing and come back to the image when you need help.
Hint: It's totally normal to have to rewrite and rearrange your work as you go! You only figure out what you want to write by writing it!