Add-Class-On-Scrolling-To-A-Specific-Element.js

jQuery(document).ready(function($){
    $(window).on('scroll', function(){
        var scrollTop = $(this).scrollTop();
        var targetTop = $('.woocommerce-product-gallery').offset().top;

        if (scrollTop >= targetTop) {
            $('.woocommerce-product-gallery').addClass('highlight');
        } else {
            $('.woocommerce-product-gallery').removeClass('highlight');
        }
    });
});