It's just a short, positive, popular, aged (last seen in 2005) word with a positive connotation and potential use in multiple markets, especially something like clothing or specifically winter apparel. Bedding/covers/duvets, energy, heating/HVAC, etc. are other uses that come to mind, and you can pretty well use it for anything that you want to project a warm, happy and safe feeling about.
It's just one of those words, that if a company really, really wants it, then you want easily make them pay for it because it makes business sense. Singular 1-words are hot right now and short word domains are where the real money comes in - and that's where the domain whales play. Companies want a shorter domain, while still maintaining the core brand, as it's easier to remember and exudes prestige in advertising and promotion.
Now as Tom at
@bmetal states, whether it gets resold or not is up to the domain gods, but Snug.ca is the kind of word ca you can make bank on, as opposed to something like SnugWinterwear.ca, which you just hope to just get a pity bid on.