That corset is a work of art, but no, it's not wearable long term (or even short term... It would be fun to try on for a little while though!). It reminds me of the Thierry Mugler / Helmut Newton collaboration from the '90s:
https://americansuburbx.com/wp-content/uploads/2011/09/206c803.jpg
Angelina there are also orthopaedic corsets in which you can't move any better and which have to be worn all day in order to work.
Orthopaedic braces don't immobilise the pelvis, and they are difficult enough to move in. (The pelvis usually requires pins).
A full body brace like a Milwaukee requires extensive therapy just to move from laying down to standing up, and that's just a spinal. Immobilising the pelvis would make it impossible. Sitting would not be an option. Walking might be possible, but it wouldn't exactly be discreet. You'd have a gait like a robot.
Pelvic movement is incredibly complex. You don't just fold in half, it's a three dimensional movement where the spine lengthens, the sacrum floats independently and you have two ball joints doing their own thing on the sides too.
For those interested, it's possible to combine a brace with something like a slimline shield. But anything more substantial than that is going to be severely restrictive. Which isn't necessarily a bad thing, depending on the circumstances... but I think it's safe to say you won't be getting out in public too much!
