The difference might be that the video is one file of 6 GB, while that "file with photo's" isn't a file but a folder that contains 6.500 files (each picture is a separate .jpg file) of 3 MB on the average.
The FAT32 limitation is on file size, not on folder content.
Still it's strange that a Windows 8 PC has a 1 TB FAT32 disk. That's why I asked you to check it. But you didn't answer yet with the results.