It is possible to expose the full prompt on a rendered image and trace back its steps with the showprompt command.  Here’s how to use it.

Step 1. First select an image by replying to it.  Note: Don’t select text.

Step 2. In the reply field, type /showprompt

This will show you the last actions taken on the image.  In the case of an image that has been processed many times, do this instead

/showprompt /history

Limitations

This is a tool that queries the database, it isn’t a command scans the image for possible prompt tokens. Thus, this also cannot read prompts from read images that were pasted as photos, and in some cases, images that were forwarded and not rendered in that channel.  In this case, it’s better to send the person a private message asking for the prompt. Worst case they’ll ignore you and best case, you get the prompt 😉