Thanks for your question and for the link to your example page. I can't see the actual
[mla_gallery] shortcode you're using to generate the gallery, but I can think of one possibility. If you post the shortcode source here I might have a different idea.
You say you "have the viewer turned to false." I assume this means you've coded
mla_viewer=false. The Google File Viewer Support only works on non-image file types, like PDF, so it does not have any effect on image file types like JPG. You can leave this parameter out unless you want thumbnail images for your PDF documents.
My guess is that you have not included a
size=none parameter in your shortcode specification. The default is
size=thumbnail, which will generate text links for the PDF documents and small images for the JPG and other image types. Give
size=none a try and see if it solves the problem. If not, post the source for your shortcode and I'll have another look.