I'm reading a translation of Hesiod's Theogony and many of the goddesses and mortal women are described as "neat-ankled" or similar. Is there a reason the ankles are singled out?
Feet and ankles were closely linked with erotic love in the ancient Greek mind. This may be the origin of the "foot size" trope in the modern world. The erotic nature of ankles lasted through the 19th century (or perhaps recurred), where cleavage or even bare breasts were not as erotic as shoulders, or lower legs and ankles.
Some of this may be clothing related. Many Greek statues, particularly of deities or aristocrats, are depicted in the "Amorgian Chiton" which was a diaphanous and sheer gown. It was considered a "sexy" bit of clothing at the time, because of how it gave both coverage, and hinted at what was underneath. The gown often ended at the ankles.
Something similar is seen today in the Middle East with ankles being overly erotic as the area you might accidentally catch a glimpse of as a woman walks - http://nytlive.nytimes.com/womenintheworld/2015/05/19/the-middle-east-and-its-glaring-hangups-with-sexuality/