In prestashop 1.6.1.24
replace: <img class="replace-2x img-responsive" src="{$link->getImageLink($product.link_rewrite, $product.id_image, 'home_default')|escape:'html':'UTF-8'}" loading="lazy" alt="{if !empty($product.legend)}{$product.legend|escape:'html':'UTF-8'}{else}{$product.name|escape:'html':'UTF-8'}{/if}" title="{if !empty($product.legend)}{$product.legend|escape:'html':'UTF-8'}{else}{$product.name|escape:'html':'UTF-8'}{/if}" {if isset($homeSize)} width="{$homeSize.width}" height="{$homeSize.height}"{/if} itemprop="image" /> with this : <img class="replace-2x img-responsive {if ($product.quantity == 0)}graypicture{/if}" src="{$link->getImageLink($product.link_rewrite, $product.id_image, 'home_default')|escape:'html':'UTF-8'}" loading="lazy" alt="{if !empty($product.legend)}{$product.legend|escape:'html':'UTF-8'}{else}{$product.name|escape:'html':'UTF-8'}{/if}" title="{if !empty($product.legend)}{$product.legend|escape:'html':'UTF-8'}{else}{$product.name|escape:'html':'UTF-8'}{/if}" {if isset($homeSize)} width="{$homeSize.width}" height="{$homeSize.height}"{/if} itemprop="image" />