Tiles Drag and Drop example masks ugly behaviour

In the Tiles Drag and Drop example:

Drag a tile into a drop area
Then drag the tile to the next drop area

While dragging, the tile now actually disappears behind the drop area. This is obfuscated by the opacity of the drop area. This behaviour not only looks ugly but is also problematic when used as a blueprint for further projects.

Please either supply a workaround in the example or highlight the issue to let people know that the example code might not be applicable to their own projects.