I don't think it's healthy to aim for looking like a model/ like the magazines. You should just aim to be healthy and fit. Having a goal is good, but if all you want to do is look like the models, then you'll never be happy or satisfied. It's this kind of thing that pushes people towards eating disorders like anorexia. Sorry, I know that this is a little rant-y, but this is an issue with a lot of girls.
No offence, but the girl in the mirror looks ridiculously photoshopped and disproportionate. You have an unreasonable idea of what a female body should look like.
Do you see the way the girl in the mirror is bending over the bike? Do you see how ridiculously skinny she is before her hips? Either she removed some ribs, or there's some computer magic going on.
I think you're missing out on the point, the point is you should strive to be healthy and exercise. And I think the reason her waist looks so small is because of the way her back is arched and her arm is in the way, but other than that it looks pretty normal, maybe a bit more on the slim side.
the girl in the mirror looks good