if you have weaver II pro, the feature image size is picked up from Main options > Post Specifics > Featured image section.
You have one setting for blog page and one for single post pages, you can choose Thumbnail, medium, or large, and these are the wordpress sizes created when you uploaded your images, based on the wordpress media settings.
But I don’t see where in your page you are using the ATW Show post or the weaver show post, can you be more specific?