As long as you don't 'seal' a canvas, you can rework the description over and over again, but it doesn't show up on it. The only way to see it is to enter the edit-mode again.
It would be great if the canvas would display whatever work in progress there is, even if it isn't yet sealed, just by looking at it. That would make it a lot easier and more intuitive to show others one's unfinished art.