Are you sure about that? The
Disney Parks blog clearly says "monorail
s". Their "artist's conception" also shows two different wraps - the yellow trail like in your photo and a blue trail.
I think there has to be more than one just because there are (at least) two monorails on the Epcot line at any given point - it's far too long a journey to just have one going back and forth, and I'm pretty sure that I remember seeing one going in opposite directions when riding that line.
Anyway - cool shot; I'm curious about your technique, too. I have a few ideas of how it could be done but I'm not sure exactly what you did.