"Replace Media File" Option Not Available

I am a new Scrivener user running Version: (64-bit), and I have inserted an image from my Resources folder into my manuscript using the following:

 <$img:Seed of Life;w=150;h=150;ebook=40%>

It works beautifully, but now I would like to update the source image without breaking the reference. After reading several different posts on this forum and digging into the manual, I learned that what I need should be in the Documents menu (Documents :arrow_forward:︎ Replace Media File). However, that option simply isn’t there despite looking with the image selected in the Binder. What am I missing?