Powershell | Sitecore | Update another field value from previous field value

$rootItem = Get-Item master:/content/Item1;  // Any item starting path

$ImagesourceTemplate = Get-Item "/sitecore/templates/Project/Presentation Templates/Article with Image"; // Template path

Get-ChildItem $rootItem.FullPath -Recurse | Where-Object { $_.TemplateName -eq $ImagesourceTemplate.Name } | ForEach-Object { 

        $_.Editing.BeginEdit()

        $titlefieldValue = $_.Fields["Title"].Value

        $_.Fields["ShortHeadline"].Value = $titlefieldValue;

        $_.Editing.EndEdit()

}

// This script will be updating all child items short headline field value from Title field value.