Dreamfall Chapters: 'Not So Dirty Dancing' Achievement
When Zoe re-enters Marcuria to find Abnaxus, you can find a group of people dancing by the fountain. If Zoe enters into the middle of this group and stands still for a few seconds, she will dance (which will unlock the achievement). Wait a few seconds after Zoe starts dancing for the achievement to unlock.
Getting the positioning JUST right can be tricky. Here's how I wedged myself in successfully. Please note that the achievement didn't unlock for me in the video because I've already unlocked it previously.