It's a typo for asymmetry, as you imagine. In this case, I imagine it means don't put your subject in the center of the frame. You might like to look up the Rule of Thirds for examples of asymmetry -- that's a Wikipedia link, but there are many more references online. Here are some images from a Google Image search.
It is definitely a typo. Alii if you had told us where you saw it, that would have helped When you search for "Chin , shoulder , hands , hourglass" on Google, all except one of the hits has the word asymmetry and they relate to Sue Bryce the photographer and her teaching. The "asymentry" is only on one slide of a pdf presentation.