A Cultural History
Looks like a JIM suit: https://en.wikipedia.org/wiki/Atmospheric_diving_suitIt is unusual, because it's sort of the reverse of a space suit. Something like that's designed for high pressure, not zero pressure.
Or for high pressure inside the Suit for moment during EVA the Crew has to reduce the internal pressure of suit to 5 or 3.7 Psi In order to keep flexibility of the suit the Hard shell Space suit can operate a normal pressure 14.7 Psi with out becoming a stiff balloon like soft space suits.
Yes, that's a good call. I've seen one-atmosphere spacesuit designs that looked like this. Does raise the question of how the other suits work. I don't think I've ever seen fictional astronauts prebreathe oxygen to decompress apart from _Rocket Girls._