Sight imagery

"The Tyrant Lizard, the most incredible monster in history."Visual imagery is written so we can see what the author describes. In A Sound of Thunder, there is a lot of visual imagery.
The muscles around his mouth formed a smile as he put his hand slowly out upon the air, and in that hand waved a check for ten thousand dollars to the man behind the desk. The reader can see  the smile an see the check waving in the man's hand.  It is good to use imagery of sight is because it describes what sight imagery is and tells a bit more about what is happening.

"A Tyrannosaurus Rex. The Tyrant Lizard, the most incredible monster in history. Sign this release. Anything happens to you, we're not responsible. Those dinosaurs are hungry."

1# The muscles around his mouth formed a smile: sight imagery

2# that hand waved a check for ten thousand dollars to the man behind the desk.: sight imagery 

You can see his smile