That is a bug which happens because your website is in a subfolder of the main domain and because you use SEF URLs.
If you change the lines
if($app->isAdmin()){
$this->uploadFolder_url = '../'.$this->uploadFolder_url;
}
to the code
if($app->isAdmin()){
$this->uploadFolder_url = '../'.$this->uploadFolder_url;
}else{
$this->uploadFolder_url = JURI::base(true).'/'.$this->uploadFolder_url;
}
near the line 15 of the file administrator/components/com_hikashop/helper/image.php, that should solve the problem. We will include this fix in next release.