Angel,
I know that it's tempting, when there's snow about, to "play" by finding an (empty) car park just to see what happens when you do certain things. Personally, I think it's a good idea to practice, even doing the wrong thing purposely to learn what to do to correct the error.
Us boys especially, like to "gun it" just to feel the wheels spinning. I don't know why, we just do. You'll notice that after doing that, the snow retained in the treads gets polished and the bond or grip that Roger has described, is much reduced.
This is why it's good advice to drive gently in snow conditions. Gently doesn't mean painfully slowly, it just means no jerks or sudden movements (snachy clutch releases, hard acceleration, swervy steering and the like) that could brake the grip that's so essential to going along in the direction you want to go, and of course stopping again the red side of the traffic light instead of buried in the side of the green-light car that unfortunately acted as you're breaking system!
Gentle driving is easier in an automatic, but with care it can be achieved in a manual, and it improves your driving skills no end. Passengers like it too, they end up at their destination feeling relaxed, instead of disheveled and feeling like they've just been rattled around in a tin can.
Lovely looking 70 BTW (there really is something about black that's so irresistible!)