Alekseolsen
Contributor
Interesting. Had forgotten that some people wear weightbelts (as per the picture above). I guess that having a weightbelt and aluminium tank makes the rig more neutral.
Doing that stunt in cold water with a drysuit and twinset** would be exceedingly dangerous and foolhardy. You'd have several kg (lb x 2) buoyancy in the drysuit, with several kg/lb of negative buoyancy on the kit. That strain would mean you wouldn't be looking like the photo above.
In summary, it's primarily a recreational and warm-water thing.
** Typical example of a steel 12 litre twinset, stainless backplate, wing, 5kg of V weights, one or two big batteries (lighting & suit heater). Drysuit would have sufficient undersuit for the temperature and duration of the dive; drygloves. Definitely no ditchable weight (which is dangerous) so under the crotch strap if used in winter.
We had to do this for my Advanced Rec Trimix course, and you are right, it doesn't look anything like on the picture, but its very doable.
And yes, in a drysuit, no weight belt and no discharge weights. The biggest pain was really threading the crotch-strap with cold fingers and drygloves on when "assembling" the rig again