New
#1
Because you have not selected those other files to be synced to your local computer.
See this tutorial: OneDrive Selective Sync - Choose Folders in Windows 10 - Windows 10 Forums
Kari
oh.
thanks for the info! +rep!
"i excluded them coz they'll occupy space on my HD."
Good that you realize these folders are separate from the same folder names in This PC. OneDrive only backs up what you put in these sub-folders, not the corresponding This PC folder. For example, if you want all your Pictures backed up, they need to be Copied to the Pictures folder in OneDrive. Cheers.