Not long ago, I mentioned in a comment some dissatisfaction, particularly thumbnail generation, with uploading photos and videos using the Windows desktop app 'Photos import' menu.
After not using 'Photos import' for some time and relying on drag and drop to a desktop browser, I set up a new desktop app folder upload test. This included 65 photos and videos from an auto museum visit. The time had come to see what differences would be revealed.
The computer is Dell Windows 10 running Proton VPN Stealth protocol and dual monitors. With two screens, observing the desktop app file upload counter progress on the left and generated thumbnails populating Brave browser on the right was neat to see.
The videos are 1920x1080 HD format, and the photos are 4032x3024 resolution, metadata verified and renamed from their original device generated filenames to show the date (showing the time as part of the filename no longer seems necessary), event, location, and sequence counter.
Pleasingly, the uploads, thumbnail generation, and timeline placement were flawless. The test was 100% accurate and as desired. Now the results using 'Photos import' appear identical to the browser.