Access Node image within Page template
In a preprocess hook (preferred):

/**
 * Implements hook_preprocess_HOOK() for page.html.twig.
 */
function MYTHEME_preprocess_page(&amp;$variables) {
  if (isset($variables['node'])) {
    $variables['image'] = $variables['node']-&gt;get('field_image')-&gt;first()-&gt;view('full');
  } 
}


Or in Twig:

{{ node.field_image.0|view('full') }}


To use |view install the module https://www.drupal.org/project/twig_tweak