I was browsing through the host of new forum posts, and came across this:
It’s perfectly understandable why this person thought the canvas was functioning incorrectly; I don’t recall there ever being any official spot showing you canvas templates. Therefore, I suggest adding an official in-game link on any canvas item which brings you to a page where you can view/download templates for the various canvas items. This way, people know what kind of format to put their pictures into for any item.