Rbadizza, you should wear length skirt with stockings and heels...definitely. Wear your hair back if it is long and don't forget the red lipstick. But if they want " short sleeve and knee length skirt.." just follow their advice - at least it will shows that you're able to follow orders strictly.
Be confident and smiley, without too much expectations - i think this is the right way to make a good impresions to the recruiters, everything else is a question of chance and luck.
Well, I wish you best of luck one more time
Not bad advice - but you'll blend in with the crowd like a chameleon. You don't have to wear your hair strictly according to Emirates grooming standards - if you do so, you will look exactly like every other wannabe in the room. Look professional, while being individual, and you'll have a better chance of the recruiters remembering you.
Thats the tricky part, getting these guys to remember who you are. They get paid minimum wage to assess hundreds of keen young people all trying their hardest to look like EK crew, and after a while, they all start to look alike. Make yourself stand out (preferably for positive reasons) and you'll stand a much better chance of getting recruited, whether the ponytail you had was regulation length or not.
For Gods Sake, if wearing bright red lipstick makes you look like Ronald MacDonald's inflatable party doll friend, don't wear it. Wear what makes YOU look good, and worry about conforming to EK standards once you get into the damn uniform.