Actually, that's the cleat. The grousers are extenders that get added to the outer edge of the track. They help decrease ground pressure by widening the track. Then the tank doesn't sink into the ground as much. M4 Sherman Jumbos had them permanently affixed.
Ice cleats are added to the center of the track, sometimes between the shoes, like the M3/5 Stuart light tanks. Sometimes like on modern German tanks, they replace track pads and are "X" shaped.