Good words Mab, however there are some folks who would rather not have the 400x300 thumbnail with a supersize link. They either want no link, or their own caption, or a larger or smaller pic. In that case you can insert your own pic into the description editor instead. Here is a post that discusses this issue:
https://community.auctiva.com/eve/forums/a/tpc/f/5796099...731047622#4731047622
Just modify the instructions of course if working with HTML.