using terminal canvas does not produce self contains html.
It relies on javascript that are either local to the computer that generated it or on a web server.
One of the advantage of canvas is that it can be read by a HTML browser, so very easy to share, I do not have to request a person analyzing data I collected to install gnuplot.
Unfortunately, as all the gnuplot are not embedded this is not really possible today except if I create a web server to hold the js script that the gnuplot generated html is referring to.
Ticket moved from /p/gnuplot/bugs/1485/