On my RAV4 PHEV there was (is) a 'wheel' that allows you to close the vents. As you drive - even with everything on the controls 'off' air still flows through the vents unless they are shut off by the 'wheel'.
However, on the YC there is no such wheel making it necessary to slide the vent lever to the side to close off the vents. This is annoying as when you wish air again, on opening the slide you need to fiddle about momentarily to select the correct direction. But that is a less expensive option to manufacture rather than the RAV system.