If cell operates reversibly than change in Gibbs energy of system equals electrical work of the cell. As far as I know electrical work is work done by electric field when charge moves between certain potential difference which in case of electrochemical cells is potential difference between two electrodes: $$ W = -zF\Delta E $$
Here work is written per mole of reactant consumed or product formed in electrochemical reaction. It is said when cell is short circuited that cell does no electrical work. How is this possible if charge moves through certain potential difference? What does the fact that there is no load connected to the cell A.K.A cell is short circuited have to do with electrical work since charge will still move between two electrodes or certain potential difference?