Dynamic Row Image Background


I am in the process of building a site where I would like to have a footer row at the end of a post template that dynamically populates with a random next post. I have managed to insert the Post Title / Categories and a Post Summary via custom fields already.

My question is this: what is the best practice to change the row background image to whatever post is currently being displayed?

I can change any row background image via custom field already, but I’d like this specific row to dynamically change depending on which post it’s decided to display when the query is set to random.

Hope this makes sense. I have searched and searched to no avail.