Microweber\Providers\UserManager::picture PHP Method

    public function picture($user_id = false)
    {
        if (!$user_id) {
            $user_id = $this->id();
        }
        $name = $this->get_by_id($user_id);
        if (isset($name['thumbnail']) and $name['thumbnail'] != '') {
            return $name['thumbnail'];
        }
    }