"Sky stroll" as it is referred to in VHD is flight. It is said that it is a thing only country bumpkins do (the he "man of steel" reference anyone?), but Laurencin loves to do it too. Most vampires, especially those affiliated with the Nobility, have this ability but prefer to travel on land or through other vehicles, because of nostalgia and unwillingness to give up traditional means of travel. There are many that do not conform to this though such as Laurencin.