Ski Canada says that they do not do any tuning on the demo skis supplied to them. They rely on the suppliers to provide well-tuned skis, with edges & bases set to the configuration that the manufacturer recommends.
The claim is that this is is an attempt to avoid introducing a change that would negatively affect performance. They let the supplier/manufacturer provide the ski with the configuration that the manufacturer believes is going to demonstrate their product in its best light. In reality, this probably creates as much of a risk that some skis don't show their best performance if the factory tune is not well suited to the conditions &/or the tester.
As much as I like the Ski Canada reviews for some general guidelines, I think they would be more useful for comparisons if they applied standard tuning configurations to each of the categories tested. Same goes for the other magazines.
If they can't standardize the tuning for their tests, I would at least like to know what the test models are set to.