Problem: What are the most important words?
event captured this rare view of moon peeking out from behind its sibling
Answer: capture, event, moon, view

Problem: What are the most important words?
Some cows grazing grass on a big steep hill.
Answer: cow, grass, graze, hill

Problem: What are the most important words?
silhouette of a happy little girl child running into the arms of his loving mother for a hug
Answer:
mother, run, silhouette