According to Wikipedia walking is defined by an ‘inverted pendulum’ gait in which the body vaults over the stiff limb or limbs with each step. This applies regardless of the number of limbs – even arthropods with six, eight or more limbs.
Wikipedia defines Hiking is an outdoor activity which consists of walking in natural environments, often in mountainous or other scenic terrain. People often hike on hiking trails.
In this picture, this activity would definitely be considered hiking. Yes hiking, no doubt about it.