There should be three different transformations if I am thinking of the correct webpart, one is the Transformation, one is the alternating transformation and one is the Selected Item Transformation. The normal transformation controls the main page where it would show up(aka higher level) - usually includes a preview of the product or document, the alternating is pretty self explanatory, but the selected item will actually be used when a product or document is selected and being viewed.
I think the proper webpart for this is the repeater. Do you see the three options that I am talking about? If not, you may be using a different webpart. If that is the case, check the properties of whatever webpart you have on the specific product page.