Copy a file from the desktop and paste it in the contentEditable element and/or the input. If you paste an image and can be read, it will be shown in the output.
Extra info available in the console
Firefox allows pasting both on the input and the div, and taking as source a file from the desktop or an image from the clipboard
It works in MacOs: https://bugs.chromium.org/p/chromium/issues/detail?id=361145
Safari. There's a file in the data, but it can't be read. https://bugs.webkit.org/show_bug.cgi?id=171504