No, it measures each cell individually because it has 12 contact points for 6 cells. If you measure from the + of the cell to the negative of the same cell, you will isolate the voltage of that particular cell, even if they are all wired in series.
Look at it this way. If all the cells were stacked in a column, end to end in series (which is the equivalent of side by side config), you could place a voltmeter across the + and negative of an individual cell, and the fact that there are more cells above or below it, makes no difference. Series only add voltage when you measure from points including more than one cell.