You have grouped products that may or may not have their own images, but you would like to also see the associated simple product's main images in the grouped carousel (gallery), and they should behave like the images normally do. And you are using the MobileShoppe theme. Done.

Open (or copy the base theme's) "mobile.phtml" located in app/design/frontend/default/mobileshoppe/template/catalog/product/view folder.

Immediately AFTER this section: