Here's my friend's definition of emo:
Emo is just a trend. Its a poppier version of goth, being goth without looking like a freak.
Musically it's the same shit they did in the 80's with synth-pop and new-romantic, just now its less synths and more guitar.
But then people took emo as an attitude or way of life, like how goth was supposed to be a genre of music, then you had goth kids and they just lived that way. All holier than thou with an attitude and all depressed.
It's more about music, but does this sound about right?