Hi Heavywoody and thanks for the enquiry.
The 'add-to-cart' functionality you require is not a feature of the free version. It is only available in the premium version of
Product Attribute Pictures.
The option to 'Ignore Product Attributes' in the free version allows you to show extra product images of any kind i.e. not necessarily related to defined product attributes. If 'Ignore Product Attributes' is set to 'No', images will only be displayed if corresponding product attributes have been defined for that product.
I hope this helps.
Nick