It was a higher scoring rate. Pakistan came out with the mood to dominate the Aussies mentally. Which they did. This pitch is not suited for a quicker long innings (60+ at around 50-60 S.R) it requires a slow batting approach if you want to last long. Pakistan chose as a plan, I believe to score fast and dominate so they can Win the match and level the series.
I think MoYo for once has shown aggression in his approach. Pakistan seem to be betting on the final test as their best display of strength, hoping they will have a full pace battery to choose from and maybe, YK also available in some reasonable form.