A mock turtleneck is much shorter, and only goes up to just below the Adam's Apple. Both styles fit snugly around the neck, as opposed to the collar on a polo shirt or an oxford shirt. We aren't opposed to men's scarves, but it's nice to toss on a sweater and not worry about styling your neckwear. Layer a lapeled jacket over your mock neck. This offers a pleasant contrast in collars and fronts. You can try this look with a casual blazer as well.