It's not so much the amplitude of price change, but the direction of both. If you open the link above, and observe carefully the chart may have explain that better. This chart is not just over weeks, but months and years.Not sure of your correlation here. Apart from the dip in November, oil compared to gold has basically gone sideways whilst gold in the same period has gone from US$750 to almost 900.
This whole week as oil has gone from 97.50 to 92.50 gold has gone the other way by around $30. In fact it has gone up this week even as the $US dollar rose.
Some weeks ago it also seemed to follow the Dow but has decoupled from this as well. The uncertainty in the markets, in particular the concern at the impending collapse of the worlds reserve currency is clearly reflected in the growing strength of the gold price
So, if you believe the co-relation movement, then the fall of the price of oil last week foretell a fall of POG soon if not in the next week.