This interpretation is a very, very clever interpretation of the rules.
They previously had a gurney there, which is a very limited device that does its trick with a lot of losses and deminishing of the cleanliness of the vortex created. They used the same trick they pioneered in '22 to get a secondary indented element (see kyles 22 analysis of the rb18), but folded and twisted the allowed single edge wing in such a way they have a "tulip" of numerous stacked elements to really smoothly roll up a massive vortex with full control and maximum vortex power. It looks like the indent at the rear of the sidepod is there to further shape and energise the vortex.
Looking at that flowvis is a thing of beauty. You can really see how that spiral of high energy air folds around the sidepod.
Speculating a bit it looks like they virtually "widen" the effect of the sidepod, pushing the front wheel wake out halfway of the sidepod, and after that they curl the high energy air back just in time to feed the diffuser wall, smashing the wake against the wheel without losing/using any of the precious highly energised air.
I'd imagine that floor vortex is very clean, powerful and cultivated as opposed to some more brute force approaches seen.
These large kicks seen on the MB and MCL just kick a big vortex up and after that it looks far less controlled and messy. It will at least be far more sensitive to wind and yaw.