Following multiple reports of the feature last month, TechCrunch sources claimed a small number of engineers are using a version of the specs that allows the winking feature to be turned on and off in the device's settings.
One source explained that the feature will take a photo instantly when the user performs an elongated wink and can even be trained to recognise the wearer's personal winking style, so to speak.
Calibrating the length of the wink required to take a photo would, of course, prevent Google Glass from snapping a pic every time you blinked, the results of which would be quite interesting if nothing else.
Don't be a winker
Just last week controversy erupted when a third-party developer created an application that offered the same functionality.
However, knowledge that the feature may have been willingly built into Google's software is likely to add to the privacy storm already surrounding the specs.
Up until recently, it was felt that users needed to vocally command the Glass unit to take a picture, but if shots can be taken even more covertly then that's a different story altogether.
Of course, it may be that Google is only testing the feature and may decide to drop it before Glass goes on sale to the public, which is likely to be sometime in late 2013/early 2014.