Hi,
Well, it's possible but it will require some development.
You'll have to edit the file "listing_img_title" of the view "product" via the menu Display>Views.
I think such change should allow you to do that:
Try changing the line:
echo '<img class="hikashop_product_listing_image" title="'.$this->escape(@$this->row->file_description).'" alt="'.$this->escape(@$this->row->file_name).'" src="'.$img->url.'"/>';
to:
if(empty($this->popup))
$this->popup = hikashop_get('helper.popup');
echo $this->popup->image('<img class="hikashop_product_listing_image" title="'.$this->escape(@$this->row->file_description).'" alt="'.$this->escape(@$this->row->file_name).'" src="'.$img->url.'"/>', $img->origin_url);
Make sure that you turn off the link to product page setting of your products listing (menu item or module) so that the popup link is not inside the link to the product page.