There's no Desktop application for Amazon Photos on Linux. Your only option is to upload through the web user interface.
If you have failures, a <div>
pops up in the lower left telling you there are failures, but there's no real way to do
anything with that information. Assuming the errors were not serious (e.g. you ran out of upload space for videos) you
probably just want to retry the failures: especially if you have 25 thousand files.
The only sensible way to extract the list of failures (there were 170 odd in my case) was to inspect the page and copy the HTML node containing the errors.
This script will take a file containing the paste of the <div>
containing the errors and create a new directory with hard
links to all the failures. You can then just upload this directory, without consuming any extra disk space. It assumes you
have saved the XML file containing the errors to the same file system as the files to upload, otherwise this won't work.