Hi there @braum, 

Welcome to the Community! Happy to help! 

I love the idea to make your customers second guess leaving a product page before they buy! While you can’t add dynamic image blocks to signup forms, there’s still a way to do this! You can  add different static image blocks to each signup form depending on the page you're looking to implement the form on, and/or the feel of the signup form.
 
Image blocks allow you to add an image to your form (e.g., your logo). You can use this block to add images to match the look and feel of your brand. JPEG, PNG, and GIF files are all accepted. As with all images viewed on the web, larger file sizes lead to slower load times. Aim for a file size of 50-100 KB for optimal performance.
 
You can also add a background image or a side image in the Styles tab of the form editor. 

Hope this helps!

-Taylor