What a surprise! A gay lib!I really think it's a dual pronged message. By focusing on a woman's appearance over her accomplishments, even when the context wouldn't naturally lend itself to do so we're saying as a culture that we feel her value is limited to her asthetics or sexual appeal. In judging her eating in doing so, we're sending the message first that the only value we hold for you as a woman is sexual and that we find no value in you as an individual. It's pretty unshakingly sexist but also pretty common, which is a shame.
Get a clue. Women focus on their own appearance. Men are just along for the enjoyment. Women wear jewelry, perfume, heels, skirts and blouses because they want to look attractive, and compete with other women.
To say her value is limited by asthetics or sexual appeal is a text book approach without any human emotion attached.
They do it because it works. You need to get out of whatever hole you live in. Try some Viagra and go hang out where some pretty woman are. Maybe you can get your heart to beat.