This feature is awesome! I had a slight problem where it generated a cool background for me but in my image was that one piece of thing I didn't want there. Instead of having to remove it myself, I used the lasso tool to select and in the generate I typed "remove" and "delete" and clicked generate. I expected it to remove that peace and merge it with the background it provided but it didn't in fact it didn't do much at all.
It would be cool, if you gave instructions to remove something on the generated pic or your pic to remove it.