I think the girl with headphone has the same clean vibe that the mac with big nose had. I will stick to it unless other suggestions gets more supporters.
Few reasons i didn't choose the mac with big nose is that it is mac, even with apple logo removed, their design stands on their own.
I disagree about the vibe. There is no life, no vibrancy. She has a nice smile, she has a nice face. Overall it's... nice. She just doesn't look like she's enjoying what she's listening to. Photoshop a headset instead of the headphones and I'd swear she's working in a call centre.
The original concert shot (which I know we can't use), the big nose one, vpsaxman's ones, even the plain shot of the monitor currently used on the website, have more life in them than that pic has.