Worked perfectly as advertised. I think since I was pulling the image from storage that I needed a full path definition (including the file: protocol).
The image files are taken from the /Pictures/ directory in the Apps file scope. The file name must be fully expanded for the image reference to work.
Note that if you want to delete the file, then you want to reference /Pictures/[filename]. So for example, image picture file name for the ListView CreateElement is file:///storage/emulated/0/Android/data/appinventor.ai_freddiegarvin.GeologyFieldTrip/files/Pictures/app_inventor_1630924067627.jpg
A call to file.delete needs /Pictures/app_inventor_1630924067627.jpg
Thanks everyone for your help.