Earlier quoted context omitted.
Just drag'n'drop an image from your desktop into the page. At least it worked for me ;)
Well, yes, it works, but there isn't an upload process, so I thought the image is linked to your local drive-- which is useless. In closer inspection, the image gets transformed to a base64 encoding (data:image/gif;base64,[...]) which is useless in this context.
Also, they're still working at the image plugin, so I think it will be improved.