It's just a fashion thing.
As Jaguar prepares to officially launch the XE sedan at the Paris Motor Show, the company has teamed up with fashion designer Stella McCartney to create a fleet of one-off XE's for the Paris Fashion Week. The FEEL XE Experience cars will be used to chauffer fashion VIPs around the city, to provide them with an "Exhilarating taste of cultural highlights that are unique to Paris". Presumably, these odd looking cars are one of those highlights.
McCartney dressed the XEs in her spring 2015 superhero print, stating "it was interesting to adapt my playful Superhero print for the XE, adding a feeling of empowerment to its exhilarating design - I can't wait to see it on the streets of Paris". We're not sure that the residents of Paris, or the VIPs who will be forced to ride in these cars, would agree with her.