In the past i've tried sending images to the client, like Add-Ons/Script_Image/image.png for example, but I've had trouble viewing it (everybody I mean). I've also noticed that since v21, the admin shield mod requires the client to have the addon, or it will just show a question mark in-place.
I know there's a way to do it in v21, Pecon7 did it with the flags on his server a couple weeks ago.
/help