How to display every pictures from all the posts on one page?

WordPress saves all images as a post type, called attachments. You will need to run a query to retrieve these attachments. You also need to specify which type of attachments you want to retrieve, as all attachments aren’t images. Videos, pdf files and audiofiles are also attachments, so you will need to specifiy the mime type to be images. Here is the query to retrieve all images

<?php 
$new_query = new WP_Query(array(
    'posts_per_page'   => 1
));

while ($new_query->have_posts()) : $new_query->the_post();
    $args = array (
        'post_type' => 'attachment',
        'numberposts' => -1,
        'status' => 'publish',
        'post_mime_type' => 'image',
        'parent' => $post->ID
    ); 

    $attachments = get_posts($args);

    if ( $attachments ) {
        foreach ( $attachments as $attachment ) {
            echo '<div class="oneCell">';
            echo '<a href="' . get_permalink( $post->ID ) . '">';
            echo wp_get_attachment_image( $attachment->ID, 'full' );
            echo '</a>';
            echo '</div>';
        }
    }
endwhile;
wp_reset_postdata();
?>

To further your reading and to learn more about the uses of WP_Query, check out the codex

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