.config-nav-block.commerceextensions-tab strong:before {
    background: url(../images/logo.png) no-repeat;
    width: 16px;
    height: 18px;
    content: '';
    display: inline-block;
    margin-right: 12px;
    vertical-align: bottom;
}

.admin__menu [data-ui-id^="menu-commerceextensions-"] .submenu-group-title span:before,
.admin__menu [data-ui-id^="menu-magento-"] [data-ui-id^="menu-magento-"] [data-ui-id^="menu-commerceextensions-"] span:before {
    background: url(../images/logo.png) no-repeat;
    width: 16px;
    height: 18px;
    content: '';
    display: inline-block;
    margin-right: 12px;
    vertical-align: top;
}