When I create a new reminder in the Reminders app with an image attached, I wanted the image to be shown in the reminder notification like shown below, it currently does not. I can make a shortcut that shows a notification with an image attached, but that doesn't work for the "Add new reminder" shortcut action. Here's a sample shortcut: https://www.icloud.com/shortcuts/65d0a673a927450187614064fabb45de
Hello, I believe the behavior your wanting is a feature provided not by the operating system directly but as a function of the code for the particular application providing the notification. That being said I do not believe the reminders application has a default set of code to handle the reminder content like that. It could easily be done provided Apple changes the application.
For more information on the exact code needed, see this: Add Image to App Notification (link for the geek programmers or wrinkle brains among us)