Hi,

For assigning different images on each product variant, in odoo 8 it can be done in the following way :-

First under tab variant of any product, add attributes of any particular product and then add attribute value against any particular attribute. Now to assign different images as per variant we need to go to Product variants and then click on any of the variant and by clicking on the edit icon(topmost left corner) in the image of any variant we can change/set images of each variant as per requirement.

For e.g. I have a product “Laptop” which is available in three different colors namely red,green and gold. Now for the user to be able to view any of the laptop variant as per color choice, we need to edit image of each variant by just clicking on the edit icon of each variant image and we can set image as per variant color.

Hope it helps

Cheers