@jane10016

I was the person who sent the original email. Apologies for writing directly to you Frank, rather than posting here. The following code snippet recreates the functionality that I was asking for. The new setup in the Drupal Juicebox module leverages the functionality of managed files and stores fewer properties in the node. I successfully used this code as part of a custom module to add photos to a gallery via a Drupal form page.

    $uri=$file->getFileUri();
    $image_info = getimagesize(\Drupal::service('file_system')->realpath($uri));
    $width=$image_info[0];
    $height=$image_info[1];
    $id=$file->id();
    
    $update_node = Node::load(278);

    if ($update_node) {
      $newimage = [
        'target_id' => $id,
        'alt' => $name,
        'title' => $title,
        'width' => $width,
        'height' => $height,
      ];

      $existing_images = $update_node->get('field_image')->getValue();
      array_unshift($existing_images, $newimage);
      $existing_images = array_slice($existing_images, 0, 42);
      $update_node->set('field_image', $existing_images);
      $update_node->save();   
    }