You hear about it all the time: a woman sues former employer, claiming she was fired because she was too fat or not pretty enough. And rather than being outraged, people accept it as a normal, acceptable behavior. Why? Well, they can do whatever they want. Besides, no one wants to shop in a store staffed by ugly people, right? No no no, the employer is within their rights to choose pretty people as a means of creating a pleasant environment.
The worst is when people go to the opposite extreme, and say things like "well you have to look nice at work, you can't just show up to a job interview dirty and shabby looking and expect to get a job." There's a difference between expecting employees to bathe, look taken care of, and wear appropriate clothing at work, and expecting female employees to look like supermodels. What does being a size 2 have anything to do with one's ability to stock merchandise and use a cash register?
Also, I do think that one's weight can affect one's job performance in some settings. If someone is obese and out of shape, and can't do the job in a timely manner or navigate around tables or merchandise fixtures, that can be a problem. If I'm eating at a restaurant, I want someone who will be able to get to me at a normal human pace and fit between the tables. And I do think flight attendants should be able to fit down the aisle of a plane.
The problem is that women are commodified in service professions. Just as night clubs and bars commodify female customers to lure in male patrons, restaurants, bars, casinos, etc. prefer female employees to look appealing to male customers in order to enhance their experience in the establishment. Female employees are used as decorations, eye candy, even expected to act as models for clothing in the retail industry.
Clothing stores often expect employees to don the store's merchandise in order to promote it. However, many places take it to the next level: they expect the employees to actually look like models. Just as print and runway models are supposed to look good in order to make the clothes look as appealing as possible (advertisers describe it as "selling a fantasy"), employees in clothing retail are expected to look just as good in order to sell the clothing they're wearing. And, of course, their appearance is supposed to create an atmosphere of beautiful people in order to enhance the shopping experience. To a lot of people, this makes appearance-based discrimination in the workplace okay. Why? It's just capitalism. If a store wants to use the appearance of their employees as a way to compete with other stores, it's their right, and in fact their prerogative in a profit-motivated economy.
And that's just one of the many reasons why I don't like capitalism. A system that allows companies to do whatever they feel appropriate to get ahead, within scant legal boundaries, also allows for the objectification of women as a tool to make money.
Again, I have no problem with basic appearance expectations. Of course people should go to work clean, having combed or brushed their hair, well dressed, man having shaved or neatened their facial hair, etc. That's reasonable. It gets to be a problem when employees are rejected or fired for being chubby or inherently "unattractive," and I even have a problem with expecting women to wear makeup and high heels, and style their hair a certain way in professions where one's appearance has nothing to do with the quality of their work. Which, aside from stripping, is pretty much every job out there.
Another problem is that these women are often harassed while at work, and while there are rules in place to protect them from male co-workers and superiors, little is ever done to protect them from male customers. Waitresses and female cashiers get hit on a lot, by entitled male customers who often get angry and offended when they're rejected, as if these women don't just exist as eye candy, but potential conquests as well. The few times I wore makeup to my job at a movie theater, I was hit on. I actually avoided makeup for the most part, because I was just going to sweat it off anyway, I didn't want guys hitting on me when I was trying to do my job, which is a topic for another time.