Well you may insert images as hyperlinks to the gridweb control matrix. Get the URLs from the dataset / datatable and set them to Hyperlink.ImageUrl property. You may store the urls into string  array and set them as Image Url(s).
Following is some simple code which works fine.
//Adds a image hyperlink.
Hyperlink linkOfImage2 = GridWeb1.WebWorksheets.Hyperlinks.AddHyperlink("B7");
//Get the web image from URL.
linkOfImage2.ImageUrl = "http://files.myopera.com/Mickeyjoe_irl/albums/38458/nissan%20cube%20in%20car%20park.jpg";
//OR get it from some inner folder in the web project.
//linkOfImage2.ImageUrl = "../style/Aspose.Grid.gif";