The star, renowned for the way she seems to purse her lips in photos, said that her mind was elsewhere most of the time she was having her picture taken.
Appearing with Whoopi Goldberg and other hosts on US show The View, she said of her pose: "I just think that's just me. Maybe it's the way my face falls, I don't know."
The singer turned fashionista added: "At the end of the day I do what I do. Half the time I'm just doing it, thinking, getting it done, sorting out the kids, you know."
Beckham also said she was sick of being considered the "funny" one in her marriage to David Beckham.
"Everybody says 'David's so handsome and she's so funny' - I'm sick of being the funny one," she said.
Asked if she still felt sexy after 10 years of marriage, she answered: "Yes I still feel sexy. We're so lucky to have each other. I really feel that with David I've met my soul mate. He's a really amazing father and a really great husband as well, yes I still feel sexy.
"I go to bed with David Beckham every night, I'm trying."
The former Spice Girl, who was wearing one of her designed dresses in grey and matching towering heels, also told her secret of looking so good every time she is photographed at an airport.
"I think it's the way I was brought up ... when you travel you always look nice.
"I always have a tracksuit or my pyjamas in my bag, so I go into the toilet - I'm a bit like Superman when I get in there, I put on something comfortable."
COMMENT RULES: Comments that are judged to be defamatory, abusive or in bad taste are not acceptable and contributors who consistently fall below certain criteria will be permanently blacklisted. The moderator will not enter into debate with individual contributors and the moderator’s decision is final. It is Belfast Telegraph policy to close comments on court cases, tribunals and active legal investigations. We may also close comments on articles which are being targeted for abuse. Problems with commenting? email@example.com
Expanding your horizons isn't possible right now. There are lots of mundane responsibilities that require your attention. Neglecting these duties will create enemies. People are relying on you to pull your weight. The sooner you tackle your work, the faster you will be able to enjoy some leisure time. Catching up on your reading, playing a sport or watching a movie will help you wind down. There are worse things than being held captive by a regular routine.More