While they were not body conscious in the way we are in many places today, they did not walk around completely exposed all of the time as that article implies. Some gowns have wider, open necklines and the bodies worn or the structure in the gown itself does provide lift and slight compression to the chest, making it more prominent. Many images you'll find in this period do cover the chest area almost fully as well. Here are a good number of portraits of different decades throughout the 16th century. Simply, breasts were not considered lewd, but it isn't practical (or warm) to walk around with them out all of the time.

There are quite a few 17th century woodcuts that show a fashion for women's dresses where the neckline was actually below the breasts. Here is an article about the fashions from the 17th and 18th centuries with some examples. Here is another article about how the fashion is depicted in woodcuts, and some more examples from an earlier time period. I also found a bunch of reposts of an article from Discovery News about a research from the University of Warwick, Angela McShane Jones, who looked into the issue in more detail and confirms that pictures of women in woodcuts from the 1600s often feature exposed breasts, not always in a negative context or in a caricature (I'm not linking out to these reposts because the sites themselves seem a bit dodgy, but you can google the title of the article, "Breast Baring Popular in 1600s".