Earlier quoted context omitted.
Really cool idea! In what browsers is dragging images to contenteditable supposed to be supported? I'm on Chrome 66 and it just opens the image in the current tab.
In Safari, Drag & Drop of images doesn't work but Copy/Paste does
Safari cut-and-paste works for images.
Of course, as the iPad runs out of memory as I use multiple apps, stops Safari then reloads it when I come back. Which loses any edits to the content.
Expected. The unexpected is that this simple thing is as functional as it is...