Hi
We only index the known fields from a merchant's datafeed.
The only option I think you have is to replace the "Image" field with the URL for the large image within the Factory. To find that field, click the "more info" link for the products.
Or you could write some logic within your views to serve up the large image when needed. It seems the pattern for their images is this:
http://www.messageproducts.com/message_assets/images/product/8MHBPCHK_m.jpg
http://www.messageproducts.com/message_assets/images/product/8MHBPCHK_e.gif
So, you could use a simple
str_replace in your views to substitute
_m.jpg with
_e.gif.
Eric