Snomes are gnomes, garden ornaments, designed for winter and Christmas. They usually come in a variety of sizes ranging from the very small - traditional garden gnome sized: about a foot high, perhaps - to the frankly huge: I have seen life-sized ones... six feet tall. They are usually representations of traditional Christmas figures: snowmen, Father Christmas (or Santa), reindeer and elves (the ones in Father Christmas' workshop, obviously, not the Tolkienesque characters... actually, I'd quite like a life seized Legolas in my garden - but no one'd get the joke) and so on, and they skulk in your garden from the end of the November until mid January.
They light up.
I don't know where the tradition came from to decorate your garden for Christmas, but it's crept up on me. In my youth, it was rather nice to see a tree with Christmas lights on. Now, they're everywhere... and nearby, there will be snomes.
I think, in principle, the idea of snomes is rather nice. Decorating your garden for Christmas shows a sense of social responsibility. Maybe it's me, but I think, practically, snomes are gaudy and quite unpleasant. They're never very well made for a start - very plasticy and badly painted in my experience of them. There seems, though, to be a measure of 'keeping up with the Joneses' about them too. If next door has snomes, then we'd better have some. That's worrying: I used to love Christmas decorations as a kid, especially outdoor ones which really were magical. But now it's a competition. How Christmassy is that?