Sticky header is activated at the time you can scroll page down. Fixed header will likely be sticked to the highest fringe of your shop. Given that this image rollover effect just isn't present in PrestaShop by default, using a PrestaShop image rollover module to get the feature is important.   This https://datashur-pro-manual94948.blogitright.com/26874945/shopping-cart-module-prestashop-secrets