This is example code that will hide the image markup for Woocommerce products if a product does not have a thumbnail. Useful if you are displaying a service for example that doesn't have a product image.

gistfile1.txt

function before_no_image_product() {
  if( !has_post_thumbnail( get_the_id() ) ){
		remove_action( 'woocommerce_before_shop_loop_item_title', 'woocommerce_template_loop_product_thumbnail', 10 );
		echo '<div class="no-image">';
	}
}
function after_no_image_product() {
	
	if( !has_post_thumbnail( get_the_id() ) ){
		add_action( 'woocommerce_before_shop_loop_item_title', 'woocommerce_template_loop_product_thumbnail', 10 );
		echo '</div>';
	}
}
function before_no_image_single_product() {
	if( !has_post_thumbnail( get_the_id() ) ){
		remove_action( 'woocommerce_before_single_product_summary', 'woocommerce_show_product_images', 20 );
		echo '<div class="no-image">';
	}
}

function after_no_image_single_product_image_restore() {
  add_action( 'woocommerce_before_single_product_summary', 'woocommerce_show_product_images', 20 );
	if( !has_post_thumbnail( get_the_id() ) ){
		echo '</div>';
	}
}

add_action( 'woocommerce_before_shop_loop_item', 'before_no_image_product', 9 );
add_action( 'woocommerce_after_shop_loop_item', 'after_no_image_product', 9 );
add_action( 'woocommerce_before_single_product_summary', 'after_no_image_single_product', 30 );
add_action( 'woocommerce_after_single_product_summary', 'after_no_image_single_product_image_restore', 30 );