Thanks dwygrsshpr. My chest freezer will be arriving at the end of this month. I sincerely hope that I'll be able to understand all this by then.
It looks like the guy at the link you posted is wiring the Love switch into an extension cord that the freezer is plugged into. From what I see of everyone's Keezer projects, that is pretty atypical. Most people seem to mount the Love on the Keezer and wire it into the appliance's wiring. In such case, I gather that the freezer would simply be plugged into a wall outlet.
In other words, the blog owner you referenced seems to be creating a Love-switched extension cord, not a Love-switched freezer. It could just as well be used to run a temperature-controlled freezer or a temperature-controlled paper shredder. But I'm guessing, because I really don't get it. Like I say, maybe I'll figure it all out when I can see the physical wiring.