I thought you couldn't do this, or at least the base code of Quest would have to be changed to act like this!
Edit: Nevermind, sorry.
It is right there in the docs!
This appears to be the standard picture frame, as far as I can tell. Does it appear different for you?
To enable it, the option is "Picture frame: a static picture that appears above text. Pictures can be set per room, or using a script command" at the bottom of the game's "Interface" tab.
Oops. Sorry, The Pixie.
Ah. So it's at the bottom of interface! Okay.