Back in the 1600's boob job technology was not precise enough to make to equally large boobs. Also, back then spirit levels were very unreliable so the boobs would often be out of level.
tbf this is accurate to real bodies. breasts are frequently mismatched in size. it's something a lot of trans women get hung up about with their own breast development, not realizing that it's really common. what makes this extra funny, though, is that she has unrealistic proportions, suggesting surgery - if your surgeon leaves you this mismatched ask for a revision lmao.