Answer:
Any word, phrase, or image that helps the readers understand and see what your describing.
Explanation:
Basically if I tell somebody a story about dogs. I could be talking about a time I took my dog to the park. To describe it I would say something like, "When I took my dog to the park yesterday, I discovered that she has a love and obsession for dog toys. Picture this, she ran over to another dog and vigorously stole the toy from a poodle." In this case, the word "vigorously" would be the word that really shows what i am talking about. It shows that my dog was being very aggressive when trying to get the toy from the poodle.