Can't move/resize circle after "add face"

I'm trying to manually add a face to a photo. In the Info window I click the "Add a Face" button. A circle with an X and a dot (i.e. the "face" circle) come up in the middle of the photo. I want to make it bigger and move it to the face in the photo, but I can't grab it. No matter where I click, no matter how I click, it's like the circle doesn't exist. The only thing I can do is click the X to remove it. What's wrong here?