An element having a holding mechanism, adapted for interacting with a functionally aligned holding mechanism of a similar element, and including a holding state and a released state. The holding mechanism in the holding state is engaged with the aligned holding mechanism of the similar element for holding the element positioned with respect to the similar element. The holding element in the released state is disengaged with the aligned holding mechanism. The element also includes a sensing mechanism for providing grab-detection, the grab-detection including detection of an action leading to a grip of the element, having a grip on the element, an action of releasing a grip of the element, and a combination thereof. The sensing mechanism is functionally coupled to the holding mechanism for upon the grab-detection actuating at least one of the functionally aligned holding mechanism between the holding state and the released state.