I just talked to my business partner (who knows more about the legal side of this stuff than I do), and here's the distinction:

You can not, by law, require a person to buy a product for a contest entry.

However, you can hold tournaments for those people who already own said product.

The manufacturer (in this case WorldWorks Games) can absolutely hold a tournament (even a contest) where the entrants are judged on a skill that's related to the product.

There is no random drawing. The law is based on chance, not skill.

Unless Canadian law is drastically different from American law, this should still hold true.

I think the main legal difference is whether it's based on chance or on skill, not what you call it. Probably ties in with all the laws on lotteries, gambling, casinos, etc. I strongly doubt there's any rules on what you're allowed to call a "contest" versus a "competition" versus a "tournament".

I'll agree with Mychal on this one.

It's nice to have minis for scale comparisons, and to see how they would fit into a build. However, that's not what a typical build-quality contest should be about.

It should be about the terrain, not the minis looking cool on the terrain.