$context = Timber::get_context();
$page = new TimberPost();

$context['page'] = $page;

if ($photos = $page->get_field('photos')) {
    $context['photos'] = $photos;
}

{% if page.photos %}

{% for p in page.photos %}

<img src="{{ p.sizes.gallery|relative }}" alt="{{ p.alt }}" />

{{ p.caption }}

{% endfor %}

{% endif %}