You can make a snapshot (System action). Then load this snapshot into a sprite. Then paste the sprite onto a canvas.
I don't know why DrawingCanvas doesn't support loading images directly, so that's the only way.
This is what I eventually settled on. My whole thing with snapshotting was that there's still the buffer of snapshotting and then loading an image from URL, which can take a bit on lower-end systems from my experience.
Thanks.