I'm not sure that's the reason why... a side impact significant enough to move the driver's seat is going to need more than another seat to absorb it...
It looks like they're testing with their homologation chassis, judging by the dot used for scanning that they've forgotten to remove from the rear main hoop gusset. Doubt that's significant, just cool - and it suggests they've already completed the part of the process that involves taking the car to Switzerland.