In Pirates of the Caribbean 4: On Stranger Tides, there's a scene where Captain Barbossa and Jack Sparrow are in a ship looking for two silver chalices.
Upon finding that the Spanish have taken the chalices, they consult a map that a skeleton on a bed is holding. However, as Jack attempts to takes the map, the skeleton his moves his head to look at Jack. At first, this seemed like the result of disturbing the skeleton, but when Jack let's go of the map, after the request of Barbossa, the skeleton stops looking at Jack as if it is somehow alive.
So my question is: What's going on? Are the actions of the Map Skeleton ever explain anywhere? Is it 'alive' or is it just moving as a result of being disturbed?