It looks to me like that's supposed to the cryo chamber the chief climbed into at the end of 3, except it looks nothing like the cryo chamber at the end of 3, and judging from those screen shots I assume he just wakes up in the new armor.
Grrr. That does not make me happy. Yes, I'm real pedantic about this issue, but I just hate it when people change stuff purely for the sake of changing it with no rhyme or reason. If it's "Oh, Cortana changed his armor while he was sleeping" thats equally stupid, because it was a destroyed ship, how on Earth (or deep space) would even a fully functional frigate have the resources to design and fabricate new super armor?
343 want to make there mark because lets face it, Halo 4 is part sequel part retooling. I don't see an issue because it still looks similar and not like its bright pink