The flight attendant uniform sends a consistent message of female service. Any uniform in general is a code of submission. However the context of the flight attendant uniform is one of travel and leisure. Through the 1970's, the pilot and flight attendant uniforms also communicated power which has decreased as travel has become more mundane. The flight attendant can still be seen, outside of the airport or inside, as a signifier for escape, getting away from wherever you are.
In the 2003 film Catch Me If You Can, the uniform alone commanded adoration and opened doors. There is also a fine line between work and leisure as both flight attendants and pilots have no work when they arrive. The clothing then is type of status symbol and an index to travel.
Check out the review of Delta uniforms by T Magazine.