Wigs, stockings and heels were associated with being of the aristocrat class. Which, as the article states, could make one wearing such things a target.
_Prior_ to the revolution, the Jacobins (who were largely bourgeoisie) would have been wearing that dress, distinguishing themselves from the working class (who _didn't_ wear the stockings). The revolutionary period is being used to illustrate a change here, not the norm.
Wigs, stockings and heels were associated with being of the aristocrat class. Which, as the article states, could make one wearing such things a target.