Default precedence product pics

Hi,

There is no mechanism in HikaShop to use the image of a category as image of a product.
If you don't specify any image in a product, the product will get the image you've configured in the "Default image" setting, under the Images section of the HikaShop configuration.
So I suppose that you must have configured the same image in that setting and in the main category of your shop.
There is however no option you can change to have HikaShop use the image of a category. That would be problematic since products can be linked to several categories and the system wouldn't know which one to use.
Now, if you really want that the product image is inherited from the category it is linked to, it's possible with some custom coding.
If you're not a developer, you would have to hire one to add that for you.