Aren't shirts like this supposed to end before the bottom of the rib cage? Maybe I've just never seen such a shirt intact. The combination of the light and the shirt might be responsible, but the model's skin looks a little odd; it almost looks like you increased the saturation on the red or magenta channel to make the shirt contrast more with the coffee cup and it threw off her skin tone.
The crop makes this shot interesting. A little steam rising from the cup would have been nice, as would increasing the saturation of the cup a bit. This is one of the more memorable images in the challenge. Most of the impact is due to the subject and composition rather than the technical photographic execution; both of the former are good, but I can't help but think that something equally striking could have been done with the execution (shooting a similar crop of the girl reflected in a coffee cup perhaps).
Nice, one of the best entries in the challenge and I gave this an 8 in accordance with that and this is pretty flawless as an image, could very well be in a commercial as far as I am concerned, except for one thing. I don´t know what it is specifically but the skintone isn´t very flattering, either it´s noise or wrong WB or something, it just looks oddly reddish, especially the hands, did you underexpose this shot and bring it back with shadow/highlights cause that might explain it? Everything else is spot on, the focus, sharpness, colours and composition.
The inclusion of the cop of coffee seems to have been done to make sure you met the challenge. However, I think that the focus of this photo is the witty saying on the t-shirt, which in itself, isn't really what the challenge is about.