create an image of the page you want [or section of the page you want] with good old alt/pint screen and get it to display as a thumbnail.

thanks, @anartist; i begun to experiment and realized that facebook looks for images in the document, its respective alts and the metadata of the page. I searched in the facebook wiki and couldnt find info about it…. iI’d like to think i didnt researched enough: this is important information and should be at hand. I tried charging images from css with display:none, but it didnt work, maybe because the alt data was missing. Well, at the end, what i did was completing the alt data on every image on my page and the metadata description and violà! But the idea of making a screen capture image may work, I’ll try it adding the alt data and post the results here!