This powered armor appears to be composed entirely of lightweight ceramic composites, rather than the usual combination of metal, and ceramic plates. It seems as though it should give even more protection than the standard, advanced power armor.
The advanced power armor Mk II is a model of power armor used exclusively by the Enclave military forces, developed after the Great War. Like its older brother, the standard advanced power armor, it's matte black with a menacing appearance, but with a few significant differences - it appears to be composed entirely of lightweight ceramic composites rather than the usual combination of metal and ceramic plates.
The advanced power armor Mk II also appears in Fallout 3 as Enclave power armor and, with a much greater resemblance, in Fallout 4 as X-01. The former is almost entirely different, bearing a stronger resemblance to power armor from Fallout Tactics: Brotherhood of Steel than to the originals, despite being referred to as "advanced power armor Mk II" by non-player characters.