Who ever created that locks up that window of the browser into full screen so you cant close it without killing the browser process. I recall being able to minimize it though.
But I read that it can really be bad if infected.
How can we use it as a joke?
Send the jpeg image in a zipped file with the instructions to open it immediately. The default unzipping program will run, then unzip to the default directory, and then The User will need to open it -which the system will detect as a plain vanilla picture file and launch the system Graphics program to display it (Gimp, Inkscape, CorelDraw, whatever). Especially if the last displayed file was set to fullscreen mode, the warning graphic will have the desired result. *grin*