Verticalization is what it sounds like.  To make something more vertical.  The dorsal processes of the vertebrae, in a neutral position, tip backward. When they are verticalized, they rotate forward which makes them more vertical. It can also make the back feel "lifted."  Lowering the neck will verticalize the dorsal processes as will poking the sternum area. If you place something like a glove on the withers and stimulate the sternum area, the glove moves forward as the vertebrae verticalize. While this may feel like lift, in motion, it is a kinematic fault as it tends to place the stance of the fore limbs too far back, which is an overloading condition.