The fragment represents the lower leg and foot of Artemis, and comes from the East end of the Parthenon frieze. As I covered in my book, The Elgin Marbles, originally the Greeks were claiming that it was Peitho - or 'Persuasion' - and saying that they hoped the return would 'persuade' the British Museum to return the Elgin Marbles ... so it's good to see that they have now studied the frieze well enough to be able to identify the figures on it.
Italy returns piece of Parthenon Marbles to Greece - NY Times.
A video can be found here.
[photos; AFP top, bottom Reuters]