WPMU folks, In creating a custom global products page

Hi WPMU folks,

In creating a custom global products page I've run into this frustration.

The thumbnails in the product list on the default /marketplace page are nice and big. Checking developer tools in Chrome I see it is grabbing the 150x150 WP thumbnail.

When I create a custom page using the global_product_list shortcode they are very small. Developer tools show it's grabbing he 50x50 WP thumbnail.

Changing the thumbnail size in shortcode has no effect.