Question about implementing DataTransfer.addElement

What's the difference between addElement and setDragImage()?

The spec says:

> The difference between setDragImage() and addElement() is that the latter
> automatically generates the image based on the current rendering of the
> elements added (potentially keeping it updated as the drag continues, e.g.
> if the elements include an actively playing video), whereas the former uses
> the exact specified image at the time the method is invoked.


For technical reasons, animating the drag image is non-trivial and not
likely to be implemented in the near future, if it is ever implemented.
However, if we don't implement dynamic drag image updates, doesn't that make
it essentially the same as setDragImage()? In that case, what's the point of
having addElement(); wouldn't it make more sense to just remove it rather
than having two different ways of doing the same thing?

Daniel