In her career that started as a U.K. kids presenter in the early 90's, Zoë would often have her belly button very blatantly showing. Whatever she was presenting, it became essential viewing. She keeps a little more covered these days, but even last year it made a brief appearance that at the time she could do nothing about as her arms were in the air, "Uh oh, belly's coming out".
There's lots of evidence out there on the web of Zoë's incredibly deep innie, here are just four great examples.
The first two are from the 90's, the 3rd one from two or three years ago on holiday, and then the last one, my most treasured scan that's sadly had to be compressed in order to be included here that's been so well lit the inside of her belly button makes a very rare appearance.
http://imgbox.com/wxVJiB69 http://imgbox.com/NTIPF5wU http://imgbox.com/AMQowtJX http://imgbox.com/DhUSufWV