File:No Screenshot.svg
If you want to change this image into another, you shouldn't look at this page, but edit the page where the screenshots are posted (most likely called "List of seriesname episodes"). Find here the correct "No Screenshot.svg" and change it to the filename of your newly uploaded image (you can upload an image with the link "Upload file" on the toolbox on the left). If you need help, you can post your question on the talk page. Please very carefully consider Wikipedia's policies on unlicensed media before adding screenshots to Wikipedia as most uses of screenshots on Wikipedia are not consistent with these policies.