Hey Hunter,
With the Format String widget (see App Store) you could create a HTML snippet that includes some JavaScript or CSS that overwrites the background image of a certain DIV with an id. Like this:
document.getElementById("specificID").style.backgroundImage = "url('img_tree.png')";
By using the Format String widget, you can use object variables in there (like the file path of the image).
Kind regards,
Bas.