sort-switch-pics.ps1

$source = '.\Album\'
$destination = '.\Switch\'

Get-ChildItem $source -PipelineVariable year |
    ForEach-Object { Get-ChildItem $year.Fullname -PipelineVariable month |
        Where-Object { $month.PSIsContainer -eq $true } |
        ForEach-Object { 
            $dest = Join-Path $destination "$year-$month"
            New-Item -Path $dest -ItemType 'directory' -Force;
                Get-ChildItem $month.FullName -Recurse |
                    Where-Object { $_.PSIsContainer -eq $false } |
                    Where-Object { !(Test-Path (Join-Path $dest $_)) } | 
                    ForEach-Object { Copy-Item $_.FullName -Destination $dest }
        }
    }