Simply user media loop

photo-loop.php

<?php if ( have_rtmedia () ) { ?>
<div class="widget">
    <h4>Recent Photos</h4>
    <div class="rtmedia-container">
        <ul class="rtmedia-list rtmedia-list-media <?php echo rtmedia_media_gallery_class (); ?>">

            <?php while ( have_rtmedia () ) : rtmedia (); ?>
                <li class="rtmedia-list-item" id="<?php echo rtmedia_id(); ?>">
                    <a href ="<?php rtmedia_permalink(); ?>" title="<?php echo rtmedia_title(); ?>" class="<?php echo apply_filters( 'rtmedia_gallery_list_item_a_class', 'rtmedia-list-item-a' ); ?>">
                        <div class="rtmedia-item-thumbnail">
                            <img src="<?php rtmedia_image("rt_media_thumbnail"); ?>" alt="<?php rtmedia_image_alt(); ?>" >
                        </div>
                    </a>
                </li>
            <?php endwhile; ?>

        </ul>
    </div>
</div>
<?php } ?>