Views product image field aggregation

Hi,
I have a views setup in which are product fields with aggregation function enabled.

The problem now is: some of the products display nodes consists of two or more products, and at the very moment at least one of them have product image attached. While viewing views generated page those product display nodes with just one image attached - does not show product image in views generated field.

I was thinking, maybe this is because views gets the last product attached to the product node? If so, can I somehow help views and say which product to show in aggregation settings by default or something with that intention?

Example:

• product list page http://ekokomfortas.lt/ekologiskos-prekes/23/2
• inside product http://ekokomfortas.lt/preke/naturalus-muilas-svelnaus-migdolu-aromato