Yes,
Another Trick Question.

Under Skimming
For Example:
Your return pump is rated for 1500 g/h and your Skimmer is only rated for 500 g/h.

More Nutrients are going back into your tank than are being filtered.
or
Dirty Water.

Over Skimming
For Example:
Your return pump is rated for 500 g/h and your Skimmer is only rated for 1500 g/h.

Less Nutrients are going back into your tank,
Better / More Mechanical Filtration.
or
Cleaner Water.