Display unique image on all slaves but toggle it off if main

In a video from MiRai I saw each window displayed a unique number (obviously representing the character / window position). I'm curious how you do this, but I'd like to expand on it a bit further.

What I'd like to do...

I have a unique image that I would like to display on each window, eg on my Mage I'd like to display IMAGE_20, on my Hunter I'd like to display IMAGE_30 etc. But, when that window becomes the main (recieves focus) I'd like to hide that image and also ensure all slaves are displaying their appropriate image.

This image can be anything, a button, a menu, a click bar, I really don't care as it will not be used for anything but display purposes.

[lax]

Start with this: http://isboxer.com/forum/viewtopic.php?f=21&t=2190

Then if you want to toggle it off on the main screen, there's a feature per Slot in your Character Set to do a Mapped Key when you switch to that window. If you're playing WoW, that will default to "JambaMaster" which switches the Jamba Addon's master character (if you're using it) to the window you switch to. In that case, you could go to the JambaMaster Mapped Key (under Always On, generally) and add a Click Bar State Action to hide it in Window:Current, and another Click Bar State Action to show it in Window:All w/o Current

Thanks for your reply. This is exactly what I was looking for.

I almost had the answer myself but this was just the nudge in the right direction I needed.