$args_query = array(
    'post_type' => array('attachment'),
    'posts_per_page' => 6,
    'order' => 'DESC',
    'orderby' => 'rand',
);

$query = new WP_Query( $args_query );

if ( $query->have_posts() ) {
    while ( $query->have_posts() ) {
        $query->the_post(); ?>
        
        <img src="<?php echo esc_url( wp_get_attachment_image_src( get_the_ID(), 'full' )[ 0 ]; ?>">
        
        <?php        
    }
} else {
    echo esc_html( 'Resim bulunamadı' );
}

wp_reset_postdata();