An articulation mechanism has a central part and a head part each made of a pair of shaped elements. The method includes detecting whether pixels corresponding to an isolated dot in the image are in an on state. Additionally, it is determined whether a type of the operation attempted includes a predefined type of operation. A subsequent attempt to pull the anchor leg upward causes the fluke to pivot into an extended position in which it provides additional resistance to the upward motion of the anchoring leg. The electronic seal is also capable of signaling the central computer when the cargo is opened.