Repro steps:

• Go to https://en.wikipedia.org/wiki/Main_Page.
  • Be sure cookies are cleared beforehand -- so as to ensure the large funding notice at the top is displayed.
• Enter element picker.
• Select the large notice at the top.
• In the element picker dialog box, pick ###centralNotice

Result:

Nothing is highlighted, merely only the contour of a zero-height box.

Fix:

The element picker should fall back on the descendants width/height for when a highlighted element has a width or height of zero.