What does "un-casual winter performance" mean?

Steven, I've put my Snow III's through some nasty off-road conditions. They have a casual/stylish look but they go full beast-mode in the elements. Would buy again.

What our copy-writers are getting at there is that these are generally a casual sneaker, but The North Face cut no corners in the design and manufacturing of these shoes. They are not meant for winter hiking, but they have ice pic technology in the sole, so they perform just as well as some of their hiking boots and winter boots. They are also waterproof, which is not a feature you generally find in casual sneakers. These shoes are pretty much amazing. I have a bike messenger friend who rides all winter through slush and snow wearing these in the Viszla Brown, and he says his feet are always warm and dry. My boyfriend wears them as his every day shoe (in the Black) and has commented that his feet have not been cold at all this winter.

This is just my opinion, but 'casual' is something that I wouldn't take out in the wild. They are probably just saying that these will likely work in more than just casual settings or uses.