Olivia Farringwood
As has been pointed out nobody is perfectly symmetric.The majority of women have a slightly larger right breast - this can be seen just within this thread where most have been larger on the right side (even checking for mirrored photos).From medical sources the disparity typically ranges up to around 3%Most people can not detect this difference and it only becomes obvious around 5-8% which is also about the same size change from menstrual cycles which makes sense as that is the minimum needed to get a potential mate's attention.This is also about the same disparity when women start to modify their clothing to compensate for or hide the differences.
Interesting. Among males the left testicle is usually the larger and lower of the two.
Exaggerated asymmetry courtesy of DeviantArtist LNMman:
I'm misshapen as well. My left one fills out an H cup with a little overflow some days. My right one is probably a medium G. Proof named them "Before and After." I think part of my not realizing I am busty has a lot to do with only looking at the smaller one. If they were even, I would like to believe I'd see them for what they are.