Hi,
This looks like you have two instances of the hikashop cart module configured differently.
When a page is displayed, your template displays the first instance of the cart module at the top. When you add a product to the cart, the system refreshes the cart dynamically in ajax. It however doesn't know which cart module to use and choose the first one it finds which is the other one and thus it looks different.
This also happens because you turned on the AJAX add to cart option of the configuration.
So you have two solutions:
1. you turn back off that AJAX option of the configuration.
2. you delete the hikashop cart module instance that you're not using.