[Custom filter by price with pre_get_posts] #woocommerce

woocommerce-pre-get-posts.php

<?php

function woocommerce_pre_get_posts( $query ) {
  
  if ( ! is_admin() && is_post_type_archive( 'product' ) && $query->is_main_query() ) {
    
    // Option 1
    $args = array(
      array(
        'meta_key'  => '_price',
        'value'     => array( 50, 500 ),
        'compare'   => 'BETWEEN'
      )
    );
    
    // Option 2
    $args = array(
      array(
        'meta_key'  => '_price',
        'value'     => array( 50, 500 ),
        'compare'   => 'BETWEEN',
        'type'      => 'NUMERIC'
      )
    );
    
    // Option 3
    $args = array(
      'relation' => 'AND',
      array(
        'meta_key'  => '_price',
        'value'     => 50,
        'compare'   => '>=',
      ),
      array(
        'meta_key'  => '_price',
        'value'     => 500,
        'compare'   => '<=',
      )
    );
    
    $query->set( 'meta_query', $args ); 
  }
}
add_action( 'pre_get_posts', 'woocommerce_pre_get_posts', 20 );

  

What is this for? I didn't get this concept.

Filter (show) woocommerce products where product price is between 50 and 500. You can use any of the 3 options all will give same result.

And what if i wanted to show only products that have an image? How would that work with the pre-get filter? Thanks in advance.