"Vertical swipe" refers to the action of sliding your finger or a stylus up or down on a touch screen device, like a smartphone or tablet, in order to scroll or navigate through content on the screen. Full definition
The steering wheel buttons are touch sensitive, the first for a car and respond with horizontal and vertical swipe movements as per a smartphone. (evo.co.uk)
Both buttons accept horizontal and vertical swiping motions. (cars.com)
The new icons are unique to Samsung, and the new vertical swiping interface makes moving through the app screens easier. (androidheadlines.com)