Context:
cp(1) has -n or --no-clobber option. It makes cp not overwrite existing files. This option is useful when you copy only newly created files.
Problem:
In PowerShell, Copy-Item cmdlet doesn't have options equivalent to --no-clobber of cp. Copy-Item -Confirm prompts you for confirmation even if there are no existing files on destination.
Solution:
You have to check existence of files on destination folder one by one.
