Product image display

-- url of the page with the problem -- : www.aromahub.com
-- HikaShop version -- : 2.6
-- Joomla version -- : 3.4.8
-- PHP version -- : 5.4.45

Dear sir
I want to have more than one product picture on the product page.But when I upload 2 pictures in the back-end ( see the attached Back-End image). It display the 2 pictures vertical instead of display 1 big picture with the small thumbnail under the big picture (See the attached Front-end image). I also want the big picture change accordingly when we hover the mouse over the underneath small thumbnail . How to fix the problem? Did I make something wrong?
Thank you very much

I have tested by changing the default template(Shape5) to Beez (Joomla template), It work fine , it show the small thumbnail correctly. As I am not a coder>
I would be appreciated if you could give me suggestion ,how to fix this issue.
Thanks again