Too funny! The machinery gets the blond models, just like car shows.
Apart from the two models giving away the goodie bags everyone else worked for the company who's stand they were on. The next two ladies are full time employees of the company they represented and although I don't know the girls in blue quite as well neither of them are models but have 'proper jobs' instead. I can assure you that none of them are dumb and all can hold their own in the rather macho world of construction machinery.
Personally I am not particularly good at working with models and it's something I avoid, give me people just being who they are anytime.