"La Mossa" is the Italian idiom for "The Move", the hip wiggle that Italian TV show hostesses do on Italian game shows. Inspector Giobi perceived Amanda doing it when Amanda stood back up after putting on protective shoe coverings before being taken into the cottage. Giobi cited it in his testimony in the Massei trial. The court had to pause while someone explained it to Amanda; she had no idea what Giobi was testifying about.
La Mossa is one of the factors that Giobi used to conclude that she is a murderer. La Mossa + Eating Pizza = Murderer. Or, to paraphrase Giobi: "We don't need no stinking evidence".
I hope readers will excuse me for speaking unkindly of major players in this case such as Stefanoni, Giobi, and Mignini. They have committed tremendous damage to the Kercher family, the two innocent defendants, and Italian justice due to their unprofessionalism. I ridicule them for it.