lib.meta.fields.ogImage = TEXT
lib.meta.fields.ogImage {
   dataProcessing {
      # Use the column 'og_image' to render an array with all relevant
      # information (such as the publicUrl)
      10 = FriendsOfTYPO3\Headless\DataProcessing\FilesProcessor
      10.as = media
      10.references.fieldName = og_image
      10.processingConfiguration.returnFlattenObject = 1

      # Extract only property 'publicUrl' from the above created array
      20 = FriendsOfTYPO3\Headless\DataProcessing\ExtractPropertyProcessor
      20.key = media.publicUrl
      20.as = media
   }
}