Hi there,
it would require custom development to achieve that, as you need to:
1. add a method of saving an Image for each menu item and the Subtitle text.
2. a PHP Snippet to filter the sub menu items to insert that image and the subtitle
For #2 you can use the PHP Snippet and accompanying CSS i created here:
https://gist.github.com/diggeddy/f38376cda0670fdbf8cb7de3ddc48f1d#file-menu-image-subtitle-php
Then use the ACF plugin to Add 2 fields to your posts:
Field for the subtitle should be named: subtitle
Field for the image should be named: menu_image and it should set to return the images ID
For each post of page that you want to have an image and subtitle you can edit that post and complete the fields.
The rest of it would need some CSS. If you want to complete the above and then share a link to your site ill take a look at that.