The FooGallery WordPress plugin provides a shortcode for embedded a gallery on a page. This shortcode can be used in WS Form.
WS Form supports WordPress shortcodes in forms using fields types such as Text Editor or HTML.
To enable the gallery to display, a small piece of JavaScript is required:
jQuery('.foogallery').foogallery();
This JavaScript needs to run on form load. This can be done very simply by using some conditional logic as shown below:
You can also use your own custom JavaScript to run scripts when a form loads. See: Run JavaScript on Form Load