Images, while not essential for the functioning of a trope article, can greatly (if only optically) increase the quality of a trope entry. However, not all trope pages that can be improved by the usage of an image have one.
Hence, this critter lists currently imageless trope pages, waiting for Wiki Magic or Image Pickin' to find and add an image. You can add one yourself to these pages; How to Pick a Good Image provides an outline of what is expected of images.
The critter also has a checkbox that allows you to classify a page as "high priority" by adding a checkmark.
Note that not all pages listed in the tool above allow for images. Some have had their images removed by Image Picking or staff decision. Either way, there will be a commented out note with instructions in the page source.